<simpara>triggers</simpara>
</listitem>
<listitem>
- <simpara>views</simpara>
+ <simpara>updatable views</simpara>
</listitem>
<listitem>
<simpara>transactional integrity</simpara>
<listitem>
<para>
These forms set or remove the default value for a column.
- The default values only apply to subsequent <command>INSERT</command>
- commands; they do not cause rows already in the table to change.
- Defaults can also be created for views, in which case they are
- inserted into <command>INSERT</> statements on the view before
- the view's <literal>ON INSERT</literal> rule is applied.
+ Default values only apply in subsequent <command>INSERT</command>
+ or <command>UPDATE</> commands; they do not cause rows already in the
+ table to change.
</para>
</listitem>
</varlistentry>
<listitem>
<para>
These forms set or remove the default value for a column.
- A default value associated with a view column is
- inserted into <command>INSERT</> statements on the view before
- the view's <literal>ON INSERT</literal> rule is applied, if
- the <command>INSERT</> does not specify a value for the column.
+ A view column's default value is substituted into any
+ <command>INSERT</> or <command>UPDATE</> command whose target is the
+ view, before applying any rules or triggers for the view. The view's
+ default will therefore take precedence over any default values from
+ underlying relations.
</para>
</listitem>
</varlistentry>
additional commands to be executed when a given command on a given
table is executed. Alternatively, an <literal>INSTEAD</literal>
rule can replace a given command by another, or cause a command
- not to be executed at all. Rules are used to implement table
+ not to be executed at all. Rules are used to implement SQL
views as well. It is important to realize that a rule is really
a command transformation mechanism, or command macro. The
- transformation happens before the execution of the commands starts.
+ transformation happens before the execution of the command starts.
If you actually want an operation that fires independently for each
physical row, you probably want to use a trigger, not a rule.
More information about the rules system is in <xref linkend="rules">.
sufficient for your purposes) to replace update actions on the view
with appropriate updates on other tables. If you want to support
<command>INSERT RETURNING</> and so on, then be sure to put a suitable
- <literal>RETURNING</> clause into each of these rules. Alternatively,
- an updatable view can be implemented using <literal>INSTEAD OF</>
- triggers (see <xref linkend="sql-createtrigger">).
+ <literal>RETURNING</> clause into each of these rules.
</para>
<para>
- There is a catch if you try to use conditional rules for view
+ There is a catch if you try to use conditional rules for complex view
updates: there <emphasis>must</> be an unconditional
<literal>INSTEAD</literal> rule for each action you wish to allow
on the view. If the rule is conditional, or is not
<literal>INSTEAD NOTHING</literal> action. (This method does not
currently work to support <literal>RETURNING</> queries, however.)
</para>
+
+ <note>
+ <para>
+ A view that is simple enough to be automatically updatable (see <xref
+ linkend="sql-createview">) does not require a user-created rule in
+ order to be updatable. While you can create an explicit rule anyway,
+ the automatic update transformation will generally outperform an
+ explicit rule.
+ </para>
+
+ <para>
+ Another alternative worth considering is to use <literal>INSTEAD OF</>
+ triggers (see <xref linkend="sql-createtrigger">) in place of rules.
+ </para>
+ </note>
</refsect1>
<refsect1>
<refsect1>
<title>Notes</title>
- <para>
- Currently, views are read only: the system will not allow an insert,
- update, or delete on a view. You can get the effect of an updatable
- view by creating <literal>INSTEAD</> triggers on the view, which
- must convert attempted inserts, etc. on the view into
- appropriate actions on other tables. For more information see
- <xref linkend="sql-createtrigger">. Another possibility is to create
- rules (see <xref linkend="sql-createrule">), but in practice triggers
- are easier to understand and use correctly.
- </para>
-
<para>
Use the <xref linkend="sql-dropview">
statement to drop views.
to replace it (this includes being a member of the owning role).
</para>
+ <refsect2 id="SQL-CREATEVIEW-updatable-views">
+ <title id="SQL-CREATEVIEW-updatable-views-title">Updatable Views</title>
+
+ <indexterm zone="sql-createview-updatable-views">
+ <primary>updatable views</primary>
+ </indexterm>
+
+ <para>
+ Simple views are automatically updatable: the system will allow
+ <command>INSERT</>, <command>UPDATE</> and <command>DELETE</> statements
+ to be used on the view in the same way as on a regular table. A view is
+ automatically updatable if it satisfies all of the following conditions:
+
+ <itemizedlist>
+ <listitem>
+ <para>
+ The view must have exactly one entry in its <literal>FROM</> list,
+ which must be a table or another updatable view.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ The view definition must not contain <literal>WITH</>,
+ <literal>DISTINCT</>, <literal>GROUP BY</>, <literal>HAVING</>,
+ <literal>LIMIT</>, or <literal>OFFSET</> clauses at the top level.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ The view definition must not contain set operations (<literal>UNION</>,
+ <literal>INTERSECT</> or <literal>EXCEPT</>) at the top level.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ All columns in the view's select list must be simple references to
+ columns of the underlying relation. They cannot be expressions,
+ literals or functions. System columns cannot be referenced, either.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ No column of the underlying relation can appear more than once in
+ the view's select list.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ The view must not have the <literal>security_barrier</> property.
+ </para>
+ </listitem>
+ </itemizedlist>
+ </para>
+
+ <para>
+ If the view is automatically updatable the system will convert any
+ <command>INSERT</>, <command>UPDATE</> or <command>DELETE</> statement
+ on the view into the corresponding statement on the underlying base
+ relation.
+ </para>
+
+ <para>
+ If an automatically updatable view contains a <literal>WHERE</>
+ condition, the condition restricts which rows of the base relation are
+ available to be modified by <command>UPDATE</> and <command>DELETE</>
+ statements on the view. However, an <command>UPDATE</> is allowed to
+ change a row so that it no longer satisfies the <literal>WHERE</>
+ condition, and thus is no longer visible through the view. Similarly,
+ an <command>INSERT</> command can potentially insert base-relation rows
+ that do not satisfy the <literal>WHERE</> condition and thus are not
+ visible through the view.
+ </para>
+
+ <para>
+ A more complex view that does not satisfy all these conditions is
+ read-only by default: the system will not allow an insert, update, or
+ delete on the view. You can get the effect of an updatable view by
+ creating <literal>INSTEAD OF</> triggers on the view, which must
+ convert attempted inserts, etc. on the view into appropriate actions
+ on other tables. For more information see <xref
+ linkend="sql-createtrigger">. Another possibility is to create rules
+ (see <xref linkend="sql-createrule">), but in practice triggers are
+ easier to understand and use correctly.
+ </para>
+
+ <para>
+ Note that the user performing the insert, update or delete on the view
+ must have the corresponding insert, update or delete privilege on the
+ view. In addition the view's owner must have the relevant privileges on
+ the underlying base relations, but the user performing the update does
+ not need any permissions on the underlying base relations (see
+ <xref linkend="rules-privileges">).
+ </para>
+ </refsect2>
</refsect1>
<refsect1>
<term><literal>CHECK OPTION</literal></term>
<listitem>
<para>
- This option has to do with updatable views. All
- <command>INSERT</> and <command>UPDATE</> commands on the view
- will be checked to ensure data satisfy the view-defining
- condition (that is, the new data would be visible through the
- view). If they do not, the update will be rejected.
+ This option controls the behavior of automatically updatable views.
+ When given, <command>INSERT</> and <command>UPDATE</> commands on
+ the view will be checked to ensure new rows satisfy the
+ view-defining condition (that is, the new rows would be visible
+ through the view). If they do not, the update will be rejected.
+ Without <literal>CHECK OPTION</literal>, <command>INSERT</> and
+ <command>UPDATE</> commands on the view are allowed to create rows
+ that are not visible through the view. (The latter behavior is the
+ only one currently provided by <productname>PostgreSQL</>.)
</para>
</listitem>
</varlistentry>
<command>CREATE OR REPLACE VIEW</command> is a
<productname>PostgreSQL</productname> language extension.
So is the concept of a temporary view.
+ The <literal>WITH</> clause is an extension as well.
</para>
</refsect1>
<para>
What happens if a view is named as the target relation for an
<command>INSERT</command>, <command>UPDATE</command>, or
- <command>DELETE</command>? Simply doing the substitutions
+ <command>DELETE</command>? Doing the substitutions
described above would give a query tree in which the result
relation points at a subquery range-table entry, which will not
- work. Instead, the rewriter assumes that the operation will be
- handled by an <literal>INSTEAD OF</> trigger on the view.
- (If there is no such trigger, the executor will throw an error
- when execution starts.) Rewriting works slightly differently
+ work. There are several ways in which <productname>PostgreSQL</>
+ can support the appearance of updating a view, however.
+</para>
+
+<para>
+ If the subquery selects from a single base relation and is simple
+ enough, the rewriter can automatically replace the subquery with the
+ underlying base relation so that the <command>INSERT</command>,
+ <command>UPDATE</command>, or <command>DELETE</command> is applied to
+ the base relation in the appropriate way. Views that are
+ <quote>simple enough</> for this are called <firstterm>automatically
+ updatable</>. For detailed information on the kinds of view that can
+ be automatically updated, see <xref linkend="sql-createview">.
+</para>
+
+<para>
+ Alternatively, the operation may be handled by a user-provided
+ <literal>INSTEAD OF</> trigger on the view.
+ Rewriting works slightly differently
in this case. For <command>INSERT</command>, the rewriter does
nothing at all with the view, leaving it as the result relation
for the query. For <command>UPDATE</command> and
</para>
<para>
- If there are no <literal>INSTEAD OF</> triggers to update the view,
- the executor will throw an error, because it cannot automatically
- update a view by itself. To change this, we can define rules that
- modify the behavior of <command>INSERT</command>,
+ Another possibility is for the user to define <literal>INSTEAD</>
+ rules that specify substitute actions for <command>INSERT</command>,
<command>UPDATE</command>, and <command>DELETE</command> commands on
a view. These rules will rewrite the command, typically into a command
that updates one or more tables, rather than views. That is the topic
evaluated first, and depending on the result, the triggers may not be
used at all.
</para>
+
+<para>
+ Automatic rewriting of an <command>INSERT</command>,
+ <command>UPDATE</command>, or <command>DELETE</command> query on a
+ simple view is always tried last. Therefore, if a view has rules or
+ triggers, they will override the default behavior of automatically
+ updatable views.
+</para>
+
+<para>
+ If there are no <literal>INSTEAD</> rules or <literal>INSTEAD OF</>
+ triggers for the view, and the rewriter cannot automatically rewrite
+ the query as an update on the underlying base relation, an error will
+ be thrown because the executor cannot update a view as such.
+</para>
+
</sect2>
</sect1>
CAST('NEVER' AS character_data) AS is_generated,
CAST(null AS character_data) AS generation_expression,
- CAST(CASE WHEN c.relkind = 'r'
- OR (c.relkind = 'v'
- AND EXISTS (SELECT 1 FROM pg_rewrite WHERE ev_class = c.oid AND ev_type = '2' AND is_instead)
- AND EXISTS (SELECT 1 FROM pg_rewrite WHERE ev_class = c.oid AND ev_type = '4' AND is_instead))
+ CAST(CASE WHEN c.relkind = 'r' OR
+ (c.relkind = 'v' AND pg_view_is_updatable(c.oid))
THEN 'YES' ELSE 'NO' END AS yes_or_no) AS is_updatable
FROM (pg_attribute a LEFT JOIN pg_attrdef ad ON attrelid = adrelid AND attnum = adnum)
CAST(nt.nspname AS sql_identifier) AS user_defined_type_schema,
CAST(t.typname AS sql_identifier) AS user_defined_type_name,
- CAST(CASE WHEN c.relkind = 'r'
- OR (c.relkind = 'v'
- AND EXISTS (SELECT 1 FROM pg_rewrite WHERE ev_class = c.oid AND ev_type = '3' AND is_instead))
+ CAST(CASE WHEN c.relkind = 'r' OR
+ (c.relkind = 'v' AND pg_view_is_insertable(c.oid))
THEN 'YES' ELSE 'NO' END AS yes_or_no) AS is_insertable_into,
CAST(CASE WHEN t.typname IS NOT NULL THEN 'YES' ELSE 'NO' END AS yes_or_no) AS is_typed,
CAST('NONE' AS character_data) AS check_option,
CAST(
- CASE WHEN EXISTS (SELECT 1 FROM pg_rewrite WHERE ev_class = c.oid AND ev_type = '2' AND is_instead)
- AND EXISTS (SELECT 1 FROM pg_rewrite WHERE ev_class = c.oid AND ev_type = '4' AND is_instead)
- THEN 'YES' ELSE 'NO' END
+ CASE WHEN pg_view_is_updatable(c.oid) THEN 'YES' ELSE 'NO' END
AS yes_or_no) AS is_updatable,
CAST(
- CASE WHEN EXISTS (SELECT 1 FROM pg_rewrite WHERE ev_class = c.oid AND ev_type = '3' AND is_instead)
- THEN 'YES' ELSE 'NO' END
+ CASE WHEN pg_view_is_insertable(c.oid) THEN 'YES' ELSE 'NO' END
AS yes_or_no) AS is_insertable_into,
CAST(
/*
* Check that a proposed result relation is a legal target for the operation
*
- * In most cases parser and/or planner should have noticed this already, but
- * let's make sure. In the view case we do need a test here, because if the
- * view wasn't rewritten by a rule, it had better have an INSTEAD trigger.
+ * Generally the parser and/or planner should have noticed any such mistake
+ * already, but let's make sure.
*
* Note: when changing this function, you probably also need to look at
* CheckValidRowMarkRel.
RelationGetRelationName(resultRel))));
break;
case RELKIND_VIEW:
+ /*
+ * Okay only if there's a suitable INSTEAD OF trigger. Messages
+ * here should match rewriteHandler.c's rewriteTargetView, except
+ * that we omit errdetail because we haven't got the information
+ * handy (and given that we really shouldn't get here anyway,
+ * it's not worth great exertion to get).
+ */
switch (operation)
{
case CMD_INSERT:
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("cannot insert into view \"%s\"",
RelationGetRelationName(resultRel)),
- errhint("You need an unconditional ON INSERT DO INSTEAD rule or an INSTEAD OF INSERT trigger.")));
+ errhint("To make the view insertable, provide an unconditional ON INSERT DO INSTEAD rule or an INSTEAD OF INSERT trigger.")));
break;
case CMD_UPDATE:
if (!trigDesc || !trigDesc->trig_update_instead_row)
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("cannot update view \"%s\"",
RelationGetRelationName(resultRel)),
- errhint("You need an unconditional ON UPDATE DO INSTEAD rule or an INSTEAD OF UPDATE trigger.")));
+ errhint("To make the view updatable, provide an unconditional ON UPDATE DO INSTEAD rule or an INSTEAD OF UPDATE trigger.")));
break;
case CMD_DELETE:
if (!trigDesc || !trigDesc->trig_delete_instead_row)
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("cannot delete from view \"%s\"",
RelationGetRelationName(resultRel)),
- errhint("You need an unconditional ON DELETE DO INSTEAD rule or an INSTEAD OF DELETE trigger.")));
+ errhint("To make the view updatable, provide an unconditional ON DELETE DO INSTEAD rule or an INSTEAD OF DELETE trigger.")));
break;
default:
elog(ERROR, "unrecognized CmdType: %d", (int) operation);
RelationGetRelationName(rel))));
break;
case RELKIND_VIEW:
- /* Should not get here */
+ /* Should not get here; planner should have expanded the view */
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("cannot lock rows in view \"%s\"",
}
+/*
+ * get_view_query - get the Query from a view's _RETURN rule.
+ *
+ * Caller should have verified that the relation is a view, and therefore
+ * we should find an ON SELECT action.
+ */
+static Query *
+get_view_query(Relation view)
+{
+ int i;
+
+ Assert(view->rd_rel->relkind == RELKIND_VIEW);
+
+ for (i = 0; i < view->rd_rules->numLocks; i++)
+ {
+ RewriteRule *rule = view->rd_rules->rules[i];
+
+ if (rule->event == CMD_SELECT)
+ {
+ /* A _RETURN rule should have only one action */
+ if (list_length(rule->actions) != 1)
+ elog(ERROR, "invalid _RETURN rule action specification");
+
+ return (Query *) linitial(rule->actions);
+ }
+ }
+
+ elog(ERROR, "failed to find _RETURN rule for view");
+ return NULL; /* keep compiler quiet */
+}
+
+
+/*
+ * view_has_instead_trigger - does view have an INSTEAD OF trigger for event?
+ *
+ * If it does, we don't want to treat it as auto-updatable. This test can't
+ * be folded into view_is_auto_updatable because it's not an error condition.
+ */
+static bool
+view_has_instead_trigger(Relation view, CmdType event)
+{
+ TriggerDesc *trigDesc = view->trigdesc;
+
+ switch (event)
+ {
+ case CMD_INSERT:
+ if (trigDesc && trigDesc->trig_insert_instead_row)
+ return true;
+ break;
+ case CMD_UPDATE:
+ if (trigDesc && trigDesc->trig_update_instead_row)
+ return true;
+ break;
+ case CMD_DELETE:
+ if (trigDesc && trigDesc->trig_delete_instead_row)
+ return true;
+ break;
+ default:
+ elog(ERROR, "unrecognized CmdType: %d", (int) event);
+ break;
+ }
+ return false;
+}
+
+
+/*
+ * view_is_auto_updatable -
+ * Test if the specified view can be automatically updated. This will
+ * either return NULL (if the view can be updated) or a message string
+ * giving the reason that it cannot be.
+ *
+ * Caller must have verified that relation is a view!
+ *
+ * Note that the checks performed here are local to this view. We do not
+ * check whether the view's underlying base relation is updatable; that
+ * will be dealt with in later, recursive processing.
+ *
+ * Also note that we don't check for INSTEAD triggers or rules here; those
+ * also prevent auto-update, but they must be checked for by the caller.
+ */
+static const char *
+view_is_auto_updatable(Relation view)
+{
+ Query *viewquery = get_view_query(view);
+ RangeTblRef *rtr;
+ RangeTblEntry *base_rte;
+ Bitmapset *bms;
+ ListCell *cell;
+
+ /*----------
+ * Check if the view is simply updatable. According to SQL-92 this means:
+ * - No DISTINCT clause.
+ * - Each TLE is a column reference, and each column appears at most once.
+ * - FROM contains exactly one base relation.
+ * - No GROUP BY or HAVING clauses.
+ * - No set operations (UNION, INTERSECT or EXCEPT).
+ * - No sub-queries in the WHERE clause that reference the target table.
+ *
+ * We ignore that last restriction since it would be complex to enforce
+ * and there isn't any actual benefit to disallowing sub-queries. (The
+ * semantic issues that the standard is presumably concerned about don't
+ * arise in Postgres, since any such sub-query will not see any updates
+ * executed by the outer query anyway, thanks to MVCC snapshotting.)
+ *
+ * In addition we impose these constraints, involving features that are
+ * not part of SQL-92:
+ * - No CTEs (WITH clauses).
+ * - No OFFSET or LIMIT clauses (this matches a SQL:2008 restriction).
+ * - No system columns (including whole-row references) in the tlist.
+ *
+ * Note that we do these checks without recursively expanding the view.
+ * If the base relation is a view, we'll recursively deal with it later.
+ *----------
+ */
+ if (viewquery->distinctClause != NIL)
+ return gettext_noop("Views containing DISTINCT are not automatically updatable.");
+
+ if (viewquery->groupClause != NIL)
+ return gettext_noop("Views containing GROUP BY are not automatically updatable.");
+
+ if (viewquery->havingQual != NULL)
+ return gettext_noop("Views containing HAVING are not automatically updatable.");
+
+ if (viewquery->setOperations != NULL)
+ return gettext_noop("Views containing UNION, INTERSECT or EXCEPT are not automatically updatable.");
+
+ if (viewquery->cteList != NIL)
+ return gettext_noop("Views containing WITH are not automatically updatable.");
+
+ if (viewquery->limitOffset != NULL || viewquery->limitCount != NULL)
+ return gettext_noop("Views containing LIMIT or OFFSET are not automatically updatable.");
+
+ /*
+ * For now, we also don't support security-barrier views, because of the
+ * difficulty of keeping upper-level qual expressions away from
+ * lower-level data. This might get relaxed in future.
+ */
+ if (RelationIsSecurityView(view))
+ return gettext_noop("Security-barrier views are not automatically updatable.");
+
+ /*
+ * The view query should select from a single base relation, which must be
+ * a table or another view.
+ */
+ if (list_length(viewquery->jointree->fromlist) != 1)
+ return gettext_noop("Views that do not select from a single table or view are not automatically updatable.");
+
+ rtr = (RangeTblRef *) linitial(viewquery->jointree->fromlist);
+ if (!IsA(rtr, RangeTblRef))
+ return gettext_noop("Views that do not select from a single table or view are not automatically updatable.");
+
+ base_rte = rt_fetch(rtr->rtindex, viewquery->rtable);
+ if (base_rte->rtekind != RTE_RELATION ||
+ (base_rte->relkind != RELKIND_RELATION &&
+ base_rte->relkind != RELKIND_VIEW))
+ return gettext_noop("Views that do not select from a single table or view are not automatically updatable.");
+
+ /*
+ * The view's targetlist entries should all be Vars referring to user
+ * columns of the base relation, and no two should refer to the same
+ * column.
+ *
+ * Note however that we should ignore resjunk entries. This proviso is
+ * relevant because ORDER BY is not disallowed, and we shouldn't reject a
+ * view defined like "SELECT * FROM t ORDER BY a+b".
+ */
+ bms = NULL;
+ foreach(cell, viewquery->targetList)
+ {
+ TargetEntry *tle = (TargetEntry *) lfirst(cell);
+ Var *var = (Var *) tle->expr;
+
+ if (tle->resjunk)
+ continue;
+
+ if (!IsA(var, Var) ||
+ var->varno != rtr->rtindex ||
+ var->varlevelsup != 0)
+ return gettext_noop("Views that return columns that are not columns of their base relation are not automatically updatable.");
+
+ if (var->varattno < 0)
+ return gettext_noop("Views that return system columns are not automatically updatable.");
+
+ if (var->varattno == 0)
+ return gettext_noop("Views that return whole-row references are not automatically updatable.");
+
+ if (bms_is_member(var->varattno, bms))
+ return gettext_noop("Views that return the same column more than once are not automatically updatable.");
+
+ bms = bms_add_member(bms, var->varattno);
+ }
+ bms_free(bms); /* just for cleanliness */
+
+ return NULL; /* the view is simply updatable */
+}
+
+
+/*
+ * relation_is_updatable - test if the specified relation is updatable.
+ *
+ * This is used for the information_schema views, which have separate concepts
+ * of "updatable" and "trigger updatable". A relation is "updatable" if it
+ * can be updated without the need for triggers (either because it has a
+ * suitable RULE, or because it is simple enough to be automatically updated).
+ *
+ * A relation is "trigger updatable" if it has a suitable INSTEAD OF trigger.
+ * The SQL standard regards this as not necessarily updatable, presumably
+ * because there is no way of knowing what the trigger will actually do.
+ * That's currently handled directly in the information_schema views, so
+ * need not be considered here.
+ *
+ * In the case of an automatically updatable view, the base relation must
+ * also be updatable.
+ *
+ * reloid is the pg_class OID to examine. req_events is a bitmask of
+ * rule event numbers; the relation is considered rule-updatable if it has
+ * all the specified rules. (We do it this way so that we can test for
+ * UPDATE plus DELETE rules in a single call.)
+ */
+bool
+relation_is_updatable(Oid reloid, int req_events)
+{
+ Relation rel;
+ RuleLock *rulelocks;
+
+ rel = try_relation_open(reloid, AccessShareLock);
+
+ /*
+ * If the relation doesn't exist, say "false" rather than throwing an
+ * error. This is helpful since scanning an information_schema view
+ * under MVCC rules can result in referencing rels that were just
+ * deleted according to a SnapshotNow probe.
+ */
+ if (rel == NULL)
+ return false;
+
+ /* Look for unconditional DO INSTEAD rules, and note supported events */
+ rulelocks = rel->rd_rules;
+ if (rulelocks != NULL)
+ {
+ int events = 0;
+ int i;
+
+ for (i = 0; i < rulelocks->numLocks; i++)
+ {
+ if (rulelocks->rules[i]->isInstead &&
+ rulelocks->rules[i]->qual == NULL)
+ {
+ events |= 1 << rulelocks->rules[i]->event;
+ }
+ }
+
+ /* If we have all rules needed, say "yes" */
+ if ((events & req_events) == req_events)
+ {
+ relation_close(rel, AccessShareLock);
+ return true;
+ }
+ }
+
+ /* Check if this is an automatically updatable view */
+ if (rel->rd_rel->relkind == RELKIND_VIEW &&
+ view_is_auto_updatable(rel) == NULL)
+ {
+ Query *viewquery;
+ RangeTblRef *rtr;
+ RangeTblEntry *base_rte;
+ Oid baseoid;
+
+ /* The base relation must also be updatable */
+ viewquery = get_view_query(rel);
+ rtr = (RangeTblRef *) linitial(viewquery->jointree->fromlist);
+ base_rte = rt_fetch(rtr->rtindex, viewquery->rtable);
+
+ if (base_rte->relkind == RELKIND_RELATION)
+ {
+ /* Tables are always updatable */
+ relation_close(rel, AccessShareLock);
+ return true;
+ }
+ else
+ {
+ /* Do a recursive check for any other kind of base relation */
+ baseoid = base_rte->relid;
+ relation_close(rel, AccessShareLock);
+ return relation_is_updatable(baseoid, req_events);
+ }
+ }
+
+ /* If we reach here, the relation is not updatable */
+ relation_close(rel, AccessShareLock);
+ return false;
+}
+
+
+/*
+ * adjust_view_column_set - map a set of column numbers according to targetlist
+ *
+ * This is used with simply-updatable views to map column-permissions sets for
+ * the view columns onto the matching columns in the underlying base relation.
+ * The targetlist is expected to be a list of plain Vars of the underlying
+ * relation (as per the checks above in view_is_auto_updatable).
+ */
+static Bitmapset *
+adjust_view_column_set(Bitmapset *cols, List *targetlist)
+{
+ Bitmapset *result = NULL;
+ Bitmapset *tmpcols;
+ AttrNumber col;
+
+ tmpcols = bms_copy(cols);
+ while ((col = bms_first_member(tmpcols)) >= 0)
+ {
+ /* bit numbers are offset by FirstLowInvalidHeapAttributeNumber */
+ AttrNumber attno = col + FirstLowInvalidHeapAttributeNumber;
+
+ if (attno == InvalidAttrNumber)
+ {
+ /*
+ * There's a whole-row reference to the view. For permissions
+ * purposes, treat it as a reference to each column available from
+ * the view. (We should *not* convert this to a whole-row
+ * reference to the base relation, since the view may not touch
+ * all columns of the base relation.)
+ */
+ ListCell *lc;
+
+ foreach(lc, targetlist)
+ {
+ TargetEntry *tle = (TargetEntry *) lfirst(lc);
+ Var *var;
+
+ if (tle->resjunk)
+ continue;
+ var = (Var *) tle->expr;
+ Assert(IsA(var, Var));
+ result = bms_add_member(result,
+ var->varattno - FirstLowInvalidHeapAttributeNumber);
+ }
+ }
+ else
+ {
+ /*
+ * Views do not have system columns, so we do not expect to see
+ * any other system attnos here. If we do find one, the error
+ * case will apply.
+ */
+ TargetEntry *tle = get_tle_by_resno(targetlist, attno);
+
+ if (tle != NULL && !tle->resjunk && IsA(tle->expr, Var))
+ {
+ Var *var = (Var *) tle->expr;
+
+ result = bms_add_member(result,
+ var->varattno - FirstLowInvalidHeapAttributeNumber);
+ }
+ else
+ elog(ERROR, "attribute number %d not found in view targetlist",
+ attno);
+ }
+ }
+ bms_free(tmpcols);
+
+ return result;
+}
+
+
+/*
+ * rewriteTargetView -
+ * Attempt to rewrite a query where the target relation is a view, so that
+ * the view's base relation becomes the target relation.
+ *
+ * Note that the base relation here may itself be a view, which may or may not
+ * have INSTEAD OF triggers or rules to handle the update. That is handled by
+ * the recursion in RewriteQuery.
+ */
+static Query *
+rewriteTargetView(Query *parsetree, Relation view)
+{
+ const char *auto_update_detail;
+ Query *viewquery;
+ RangeTblRef *rtr;
+ int base_rt_index;
+ int new_rt_index;
+ RangeTblEntry *base_rte;
+ RangeTblEntry *view_rte;
+ RangeTblEntry *new_rte;
+ Relation base_rel;
+ List *view_targetlist;
+ ListCell *lc;
+
+ /* The view must be simply updatable, else fail */
+ auto_update_detail = view_is_auto_updatable(view);
+ if (auto_update_detail)
+ {
+ /* messages here should match execMain.c's CheckValidResultRel */
+ switch (parsetree->commandType)
+ {
+ case CMD_INSERT:
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("cannot insert into view \"%s\"",
+ RelationGetRelationName(view)),
+ errdetail_internal("%s", _(auto_update_detail)),
+ errhint("To make the view insertable, provide an unconditional ON INSERT DO INSTEAD rule or an INSTEAD OF INSERT trigger.")));
+ break;
+ case CMD_UPDATE:
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("cannot update view \"%s\"",
+ RelationGetRelationName(view)),
+ errdetail_internal("%s", _(auto_update_detail)),
+ errhint("To make the view updatable, provide an unconditional ON UPDATE DO INSTEAD rule or an INSTEAD OF UPDATE trigger.")));
+ break;
+ case CMD_DELETE:
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("cannot delete from view \"%s\"",
+ RelationGetRelationName(view)),
+ errdetail_internal("%s", _(auto_update_detail)),
+ errhint("To make the view updatable, provide an unconditional ON DELETE DO INSTEAD rule or an INSTEAD OF DELETE trigger.")));
+ break;
+ default:
+ elog(ERROR, "unrecognized CmdType: %d",
+ (int) parsetree->commandType);
+ break;
+ }
+ }
+
+ /* Locate RTE describing the view in the outer query */
+ view_rte = rt_fetch(parsetree->resultRelation, parsetree->rtable);
+
+ /*
+ * If we get here, view_is_auto_updatable() has verified that the view
+ * contains a single base relation.
+ */
+ viewquery = get_view_query(view);
+
+ Assert(list_length(viewquery->jointree->fromlist) == 1);
+ rtr = (RangeTblRef *) linitial(viewquery->jointree->fromlist);
+ Assert(IsA(rtr, RangeTblRef));
+
+ base_rt_index = rtr->rtindex;
+ base_rte = rt_fetch(base_rt_index, viewquery->rtable);
+ Assert(base_rte->rtekind == RTE_RELATION);
+
+ /*
+ * Up to now, the base relation hasn't been touched at all in our query.
+ * We need to acquire lock on it before we try to do anything with it.
+ * (The subsequent recursive call of RewriteQuery will suppose that we
+ * already have the right lock!) Since it will become the query target
+ * relation, RowExclusiveLock is always the right thing.
+ */
+ base_rel = heap_open(base_rte->relid, RowExclusiveLock);
+
+ /*
+ * While we have the relation open, update the RTE's relkind, just in case
+ * it changed since this view was made (cf. AcquireRewriteLocks).
+ */
+ base_rte->relkind = base_rel->rd_rel->relkind;
+
+ heap_close(base_rel, NoLock);
+
+ /*
+ * Create a new target RTE describing the base relation, and add it to the
+ * outer query's rangetable. (What's happening in the next few steps is
+ * very much like what the planner would do to "pull up" the view into the
+ * outer query. Perhaps someday we should refactor things enough so that
+ * we can share code with the planner.)
+ */
+ new_rte = (RangeTblEntry *) copyObject(base_rte);
+ parsetree->rtable = lappend(parsetree->rtable, new_rte);
+ new_rt_index = list_length(parsetree->rtable);
+
+ /*
+ * Make a copy of the view's targetlist, adjusting its Vars to reference
+ * the new target RTE, ie make their varnos be new_rt_index instead of
+ * base_rt_index. There can be no Vars for other rels in the tlist, so
+ * this is sufficient to pull up the tlist expressions for use in the
+ * outer query. The tlist will provide the replacement expressions used
+ * by ReplaceVarsFromTargetList below.
+ */
+ view_targetlist = copyObject(viewquery->targetList);
+
+ ChangeVarNodes((Node *) view_targetlist,
+ base_rt_index,
+ new_rt_index,
+ 0);
+
+ /*
+ * Mark the new target RTE for the permissions checks that we want to
+ * enforce against the view owner, as distinct from the query caller. At
+ * the relation level, require the same INSERT/UPDATE/DELETE permissions
+ * that the query caller needs against the view. We drop the ACL_SELECT
+ * bit that is presumably in new_rte->requiredPerms initially.
+ *
+ * Note: the original view RTE remains in the query's rangetable list.
+ * Although it will be unused in the query plan, we need it there so that
+ * the executor still performs appropriate permissions checks for the
+ * query caller's use of the view.
+ */
+ new_rte->checkAsUser = view->rd_rel->relowner;
+ new_rte->requiredPerms = view_rte->requiredPerms;
+
+ /*
+ * Now for the per-column permissions bits.
+ *
+ * Initially, new_rte contains selectedCols permission check bits for all
+ * base-rel columns referenced by the view, but since the view is a SELECT
+ * query its modifiedCols is empty. We set modifiedCols to include all
+ * the columns the outer query is trying to modify, adjusting the column
+ * numbers as needed. But we leave selectedCols as-is, so the view owner
+ * must have read permission for all columns used in the view definition,
+ * even if some of them are not read by the outer query. We could try to
+ * limit selectedCols to only columns used in the transformed query, but
+ * that does not correspond to what happens in ordinary SELECT usage of a
+ * view: all referenced columns must have read permission, even if
+ * optimization finds that some of them can be discarded during query
+ * transformation. The flattening we're doing here is an optional
+ * optimization, too. (If you are unpersuaded and want to change this,
+ * note that applying adjust_view_column_set to view_rte->selectedCols is
+ * clearly *not* the right answer, since that neglects base-rel columns
+ * used in the view's WHERE quals.)
+ *
+ * This step needs the modified view targetlist, so we have to do things
+ * in this order.
+ */
+ Assert(bms_is_empty(new_rte->modifiedCols));
+ new_rte->modifiedCols = adjust_view_column_set(view_rte->modifiedCols,
+ view_targetlist);
+
+ /*
+ * For UPDATE/DELETE, rewriteTargetListUD will have added a wholerow junk
+ * TLE for the view to the end of the targetlist, which we no longer need.
+ * Remove it to avoid unnecessary work when we process the targetlist.
+ * Note that when we recurse through rewriteQuery a new junk TLE will be
+ * added to allow the executor to find the proper row in the new target
+ * relation. (So, if we failed to do this, we might have multiple junk
+ * TLEs with the same name, which would be disastrous.)
+ */
+ if (parsetree->commandType != CMD_INSERT)
+ {
+ TargetEntry *tle = (TargetEntry *) llast(parsetree->targetList);
+
+ Assert(tle->resjunk);
+ Assert(IsA(tle->expr, Var) &&
+ ((Var *) tle->expr)->varno == parsetree->resultRelation &&
+ ((Var *) tle->expr)->varattno == 0);
+ parsetree->targetList = list_delete_ptr(parsetree->targetList, tle);
+ }
+
+ /*
+ * Now update all Vars in the outer query that reference the view to
+ * reference the appropriate column of the base relation instead.
+ */
+ parsetree = (Query *)
+ ReplaceVarsFromTargetList((Node *) parsetree,
+ parsetree->resultRelation,
+ 0,
+ view_rte,
+ view_targetlist,
+ REPLACEVARS_REPORT_ERROR,
+ 0,
+ &parsetree->hasSubLinks);
+
+ /*
+ * Update all other RTI references in the query that point to the view
+ * (for example, parsetree->resultRelation itself) to point to the new
+ * base relation instead. Vars will not be affected since none of them
+ * reference parsetree->resultRelation any longer.
+ */
+ ChangeVarNodes((Node *) parsetree,
+ parsetree->resultRelation,
+ new_rt_index,
+ 0);
+ Assert(parsetree->resultRelation == new_rt_index);
+
+ /*
+ * For INSERT/UPDATE we must also update resnos in the targetlist to refer
+ * to columns of the base relation, since those indicate the target
+ * columns to be affected.
+ *
+ * Note that this destroys the resno ordering of the targetlist, but that
+ * will be fixed when we recurse through rewriteQuery, which will invoke
+ * rewriteTargetListIU again on the updated targetlist.
+ */
+ if (parsetree->commandType != CMD_DELETE)
+ {
+ foreach(lc, parsetree->targetList)
+ {
+ TargetEntry *tle = (TargetEntry *) lfirst(lc);
+ TargetEntry *view_tle;
+
+ if (tle->resjunk)
+ continue;
+
+ view_tle = get_tle_by_resno(view_targetlist, tle->resno);
+ if (view_tle != NULL && !view_tle->resjunk && IsA(view_tle->expr, Var))
+ tle->resno = ((Var *) view_tle->expr)->varattno;
+ else
+ elog(ERROR, "attribute number %d not found in view targetlist",
+ tle->resno);
+ }
+ }
+
+ /*
+ * For UPDATE/DELETE, pull up any WHERE quals from the view. We know that
+ * any Vars in the quals must reference the one base relation, so we need
+ * only adjust their varnos to reference the new target (just the same as
+ * we did with the view targetlist).
+ *
+ * For INSERT, the view's quals can be ignored for now. When we implement
+ * WITH CHECK OPTION, this might be a good place to collect them.
+ */
+ if (parsetree->commandType != CMD_INSERT &&
+ viewquery->jointree->quals != NULL)
+ {
+ Node *viewqual = (Node *) copyObject(viewquery->jointree->quals);
+
+ ChangeVarNodes(viewqual, base_rt_index, new_rt_index, 0);
+ AddQual(parsetree, (Node *) viewqual);
+ }
+
+ return parsetree;
+}
+
+
/*
* RewriteQuery -
* rewrites the query and apply the rules again on the queries rewritten
RangeTblEntry *rt_entry;
Relation rt_entry_relation;
List *locks;
+ List *product_queries;
result_relation = parsetree->resultRelation;
Assert(result_relation != 0);
locks = matchLocks(event, rt_entry_relation->rd_rules,
result_relation, parsetree);
- if (locks != NIL)
+ product_queries = fireRules(parsetree,
+ result_relation,
+ event,
+ locks,
+ &instead,
+ &returning,
+ &qual_product);
+
+ /*
+ * If there were no INSTEAD rules, and the target relation is a view
+ * without any INSTEAD OF triggers, see if the view can be
+ * automatically updated. If so, we perform the necessary query
+ * transformation here and add the resulting query to the
+ * product_queries list, so that it gets recursively rewritten if
+ * necessary.
+ */
+ if (!instead && qual_product == NULL &&
+ rt_entry_relation->rd_rel->relkind == RELKIND_VIEW &&
+ !view_has_instead_trigger(rt_entry_relation, event))
{
- List *product_queries;
+ /*
+ * This throws an error if the view can't be automatically
+ * updated, but that's OK since the query would fail at runtime
+ * anyway.
+ */
+ parsetree = rewriteTargetView(parsetree, rt_entry_relation);
- product_queries = fireRules(parsetree,
- result_relation,
- event,
- locks,
- &instead,
- &returning,
- &qual_product);
+ /*
+ * At this point product_queries contains any DO ALSO rule actions.
+ * Add the rewritten query before or after those. This must match
+ * the handling the original query would have gotten below, if
+ * we allowed it to be included again.
+ */
+ if (parsetree->commandType == CMD_INSERT)
+ product_queries = lcons(parsetree, product_queries);
+ else
+ product_queries = lappend(product_queries, parsetree);
+
+ /*
+ * Set the "instead" flag, as if there had been an unqualified
+ * INSTEAD, to prevent the original query from being included a
+ * second time below. The transformation will have rewritten any
+ * RETURNING list, so we can also set "returning" to forestall
+ * throwing an error below.
+ */
+ instead = true;
+ returning = true;
+ }
/*
* If we got any product queries, recursively rewrite them --- but
rewrite_events = list_delete_first(rewrite_events);
}
- }
/*
* If there is an INSTEAD, and the original query has a RETURNING, we
#include "miscadmin.h"
#include "parser/keywords.h"
#include "postmaster/syslogger.h"
+#include "rewrite/rewriteHandler.h"
#include "storage/fd.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
PG_RETURN_NULL();
PG_RETURN_TEXT_P(cstring_to_text(generate_collation_name(collid)));
}
+
+
+/*
+ * information_schema support functions
+ *
+ * Test whether a view (identified by pg_class OID) is insertable-into or
+ * updatable. The latter requires delete capability too. This is an
+ * artifact of the way the SQL standard defines the information_schema views:
+ * if we defined separate functions for update and delete, we'd double the
+ * work required to compute the view columns.
+ *
+ * These rely on relation_is_updatable(), which is in rewriteHandler.c.
+ */
+Datum
+pg_view_is_insertable(PG_FUNCTION_ARGS)
+{
+ Oid viewoid = PG_GETARG_OID(0);
+ int req_events = (1 << CMD_INSERT);
+
+ PG_RETURN_BOOL(relation_is_updatable(viewoid, req_events));
+}
+
+Datum
+pg_view_is_updatable(PG_FUNCTION_ARGS)
+{
+ Oid viewoid = PG_GETARG_OID(0);
+ int req_events = (1 << CMD_UPDATE) | (1 << CMD_DELETE);
+
+ PG_RETURN_BOOL(relation_is_updatable(viewoid, req_events));
+}
*/
/* yyyymmddN */
-#define CATALOG_VERSION_NO 201211281
+#define CATALOG_VERSION_NO 201212081
#endif
DATA(insert OID = 3162 ( pg_collation_for PGNSP PGUID 12 1 0 0 0 f f f f f f s 1 0 25 "2276" _null_ _null_ _null_ _null_ pg_collation_for _null_ _null_ _null_ ));
DESCR("collation of the argument; implementation of the COLLATION FOR expression");
+DATA(insert OID = 3842 ( pg_view_is_insertable PGNSP PGUID 12 10 0 0 0 f f f f t f s 1 0 16 "26" _null_ _null_ _null_ _null_ pg_view_is_insertable _null_ _null_ _null_ ));
+DESCR("is a view insertable-into");
+DATA(insert OID = 3843 ( pg_view_is_updatable PGNSP PGUID 12 10 0 0 0 f f f f t f s 1 0 16 "26" _null_ _null_ _null_ _null_ pg_view_is_updatable _null_ _null_ _null_ ));
+DESCR("is a view updatable");
+
/* Deferrable unique constraint trigger */
DATA(insert OID = 1250 ( unique_key_recheck PGNSP PGUID 12 1 0 0 0 f f f f t f v 0 0 2279 "" _null_ _null_ _null_ _null_ unique_key_recheck _null_ _null_ _null_ ));
DESCR("deferred UNIQUE constraint check");
extern List *QueryRewrite(Query *parsetree);
extern void AcquireRewriteLocks(Query *parsetree, bool forUpdatePushedDown);
+
extern Node *build_column_default(Relation rel, int attrno);
+extern bool relation_is_updatable(Oid reloid, int req_events);
#endif /* REWRITEHANDLER_H */
extern Datum pg_get_keywords(PG_FUNCTION_ARGS);
extern Datum pg_typeof(PG_FUNCTION_ARGS);
extern Datum pg_collation_for(PG_FUNCTION_ARGS);
+extern Datum pg_view_is_insertable(PG_FUNCTION_ARGS);
+extern Datum pg_view_is_updatable(PG_FUNCTION_ARGS);
/* oid.c */
extern Datum oidin(PG_FUNCTION_ARGS);
-- Test triggers on views
--
CREATE VIEW main_view AS SELECT a, b FROM main_table;
--- Updates should fail without rules or triggers
-INSERT INTO main_view VALUES (1,2);
-ERROR: cannot insert into view "main_view"
-HINT: You need an unconditional ON INSERT DO INSTEAD rule or an INSTEAD OF INSERT trigger.
-UPDATE main_view SET b = 20 WHERE a = 50;
-ERROR: cannot update view "main_view"
-HINT: You need an unconditional ON UPDATE DO INSTEAD rule or an INSTEAD OF UPDATE trigger.
-DELETE FROM main_view WHERE a = 50;
-ERROR: cannot delete from view "main_view"
-HINT: You need an unconditional ON DELETE DO INSTEAD rule or an INSTEAD OF DELETE trigger.
--- Should fail even when there are no matching rows
-DELETE FROM main_view WHERE a = 51;
-ERROR: cannot delete from view "main_view"
-HINT: You need an unconditional ON DELETE DO INSTEAD rule or an INSTEAD OF DELETE trigger.
-- VIEW trigger function
CREATE OR REPLACE FUNCTION view_trigger() RETURNS trigger
LANGUAGE plpgsql AS $$
--- /dev/null
+--
+-- UPDATABLE VIEWS
+--
+-- check that non-updatable views are rejected with useful error messages
+CREATE TABLE base_tbl (a int PRIMARY KEY, b text DEFAULT 'Unspecified');
+INSERT INTO base_tbl SELECT i, 'Row ' || i FROM generate_series(-2, 2) g(i);
+CREATE VIEW ro_view1 AS SELECT DISTINCT a, b FROM base_tbl; -- DISTINCT not supported
+CREATE VIEW ro_view2 AS SELECT a, b FROM base_tbl GROUP BY a, b; -- GROUP BY not supported
+CREATE VIEW ro_view3 AS SELECT 1 FROM base_tbl HAVING max(a) > 0; -- HAVING not supported
+CREATE VIEW ro_view4 AS SELECT count(*) FROM base_tbl; -- Aggregate functions not supported
+CREATE VIEW ro_view5 AS SELECT a, rank() OVER() FROM base_tbl; -- Window functions not supported
+CREATE VIEW ro_view6 AS SELECT a, b FROM base_tbl UNION SELECT -a, b FROM base_tbl; -- Set ops not supported
+CREATE VIEW ro_view7 AS WITH t AS (SELECT a, b FROM base_tbl) SELECT * FROM t; -- WITH not supported
+CREATE VIEW ro_view8 AS SELECT a, b FROM base_tbl ORDER BY a OFFSET 1; -- OFFSET not supported
+CREATE VIEW ro_view9 AS SELECT a, b FROM base_tbl ORDER BY a LIMIT 1; -- LIMIT not supported
+CREATE VIEW ro_view10 AS SELECT 1 AS a; -- No base relations
+CREATE VIEW ro_view11 AS SELECT b1.a, b2.b FROM base_tbl b1, base_tbl b2; -- Multiple base relations
+CREATE VIEW ro_view12 AS SELECT * FROM generate_series(1, 10) AS g(a); -- SRF in rangetable
+CREATE VIEW ro_view13 AS SELECT a, b FROM (SELECT * FROM base_tbl) AS t; -- Subselect in rangetable
+CREATE VIEW ro_view14 AS SELECT ctid FROM base_tbl; -- System columns not supported
+CREATE VIEW ro_view15 AS SELECT a, upper(b) FROM base_tbl; -- Expression/function in targetlist
+CREATE VIEW ro_view16 AS SELECT a, b, a AS aa FROM base_tbl; -- Repeated column
+CREATE VIEW ro_view17 AS SELECT * FROM ro_view1; -- Base relation not updatable
+CREATE VIEW ro_view18 WITH (security_barrier = true)
+ AS SELECT * FROM base_tbl; -- Security barrier views not updatable
+CREATE VIEW ro_view19 AS SELECT * FROM (VALUES(1)) AS tmp(a); -- VALUES in rangetable
+CREATE SEQUENCE seq;
+CREATE VIEW ro_view20 AS SELECT * FROM seq; -- View based on a sequence
+SELECT table_name, is_insertable_into
+ FROM information_schema.tables
+ WHERE table_name LIKE 'ro_view%'
+ ORDER BY table_name;
+ table_name | is_insertable_into
+------------+--------------------
+ ro_view1 | NO
+ ro_view10 | NO
+ ro_view11 | NO
+ ro_view12 | NO
+ ro_view13 | NO
+ ro_view14 | NO
+ ro_view15 | NO
+ ro_view16 | NO
+ ro_view17 | NO
+ ro_view18 | NO
+ ro_view19 | NO
+ ro_view2 | NO
+ ro_view20 | NO
+ ro_view3 | NO
+ ro_view4 | NO
+ ro_view5 | NO
+ ro_view6 | NO
+ ro_view7 | NO
+ ro_view8 | NO
+ ro_view9 | NO
+(20 rows)
+
+SELECT table_name, is_updatable, is_insertable_into
+ FROM information_schema.views
+ WHERE table_name LIKE 'ro_view%'
+ ORDER BY table_name;
+ table_name | is_updatable | is_insertable_into
+------------+--------------+--------------------
+ ro_view1 | NO | NO
+ ro_view10 | NO | NO
+ ro_view11 | NO | NO
+ ro_view12 | NO | NO
+ ro_view13 | NO | NO
+ ro_view14 | NO | NO
+ ro_view15 | NO | NO
+ ro_view16 | NO | NO
+ ro_view17 | NO | NO
+ ro_view18 | NO | NO
+ ro_view19 | NO | NO
+ ro_view2 | NO | NO
+ ro_view20 | NO | NO
+ ro_view3 | NO | NO
+ ro_view4 | NO | NO
+ ro_view5 | NO | NO
+ ro_view6 | NO | NO
+ ro_view7 | NO | NO
+ ro_view8 | NO | NO
+ ro_view9 | NO | NO
+(20 rows)
+
+SELECT table_name, column_name, is_updatable
+ FROM information_schema.columns
+ WHERE table_name LIKE 'ro_view%'
+ ORDER BY table_name, ordinal_position;
+ table_name | column_name | is_updatable
+------------+---------------+--------------
+ ro_view1 | a | NO
+ ro_view1 | b | NO
+ ro_view10 | a | NO
+ ro_view11 | a | NO
+ ro_view11 | b | NO
+ ro_view12 | a | NO
+ ro_view13 | a | NO
+ ro_view13 | b | NO
+ ro_view14 | ctid | NO
+ ro_view15 | a | NO
+ ro_view15 | upper | NO
+ ro_view16 | a | NO
+ ro_view16 | b | NO
+ ro_view16 | aa | NO
+ ro_view17 | a | NO
+ ro_view17 | b | NO
+ ro_view18 | a | NO
+ ro_view18 | b | NO
+ ro_view19 | a | NO
+ ro_view2 | a | NO
+ ro_view2 | b | NO
+ ro_view20 | sequence_name | NO
+ ro_view20 | last_value | NO
+ ro_view20 | start_value | NO
+ ro_view20 | increment_by | NO
+ ro_view20 | max_value | NO
+ ro_view20 | min_value | NO
+ ro_view20 | cache_value | NO
+ ro_view20 | log_cnt | NO
+ ro_view20 | is_cycled | NO
+ ro_view20 | is_called | NO
+ ro_view3 | ?column? | NO
+ ro_view4 | count | NO
+ ro_view5 | a | NO
+ ro_view5 | rank | NO
+ ro_view6 | a | NO
+ ro_view6 | b | NO
+ ro_view7 | a | NO
+ ro_view7 | b | NO
+ ro_view8 | a | NO
+ ro_view8 | b | NO
+ ro_view9 | a | NO
+ ro_view9 | b | NO
+(43 rows)
+
+DELETE FROM ro_view1;
+ERROR: cannot delete from view "ro_view1"
+DETAIL: Views containing DISTINCT are not automatically updatable.
+HINT: To make the view updatable, provide an unconditional ON DELETE DO INSTEAD rule or an INSTEAD OF DELETE trigger.
+DELETE FROM ro_view2;
+ERROR: cannot delete from view "ro_view2"
+DETAIL: Views containing GROUP BY are not automatically updatable.
+HINT: To make the view updatable, provide an unconditional ON DELETE DO INSTEAD rule or an INSTEAD OF DELETE trigger.
+DELETE FROM ro_view3;
+ERROR: cannot delete from view "ro_view3"
+DETAIL: Views containing HAVING are not automatically updatable.
+HINT: To make the view updatable, provide an unconditional ON DELETE DO INSTEAD rule or an INSTEAD OF DELETE trigger.
+DELETE FROM ro_view4;
+ERROR: cannot delete from view "ro_view4"
+DETAIL: Views that return columns that are not columns of their base relation are not automatically updatable.
+HINT: To make the view updatable, provide an unconditional ON DELETE DO INSTEAD rule or an INSTEAD OF DELETE trigger.
+DELETE FROM ro_view5;
+ERROR: cannot delete from view "ro_view5"
+DETAIL: Views that return columns that are not columns of their base relation are not automatically updatable.
+HINT: To make the view updatable, provide an unconditional ON DELETE DO INSTEAD rule or an INSTEAD OF DELETE trigger.
+DELETE FROM ro_view6;
+ERROR: cannot delete from view "ro_view6"
+DETAIL: Views containing UNION, INTERSECT or EXCEPT are not automatically updatable.
+HINT: To make the view updatable, provide an unconditional ON DELETE DO INSTEAD rule or an INSTEAD OF DELETE trigger.
+UPDATE ro_view7 SET a=a+1;
+ERROR: cannot update view "ro_view7"
+DETAIL: Views containing WITH are not automatically updatable.
+HINT: To make the view updatable, provide an unconditional ON UPDATE DO INSTEAD rule or an INSTEAD OF UPDATE trigger.
+UPDATE ro_view8 SET a=a+1;
+ERROR: cannot update view "ro_view8"
+DETAIL: Views containing LIMIT or OFFSET are not automatically updatable.
+HINT: To make the view updatable, provide an unconditional ON UPDATE DO INSTEAD rule or an INSTEAD OF UPDATE trigger.
+UPDATE ro_view9 SET a=a+1;
+ERROR: cannot update view "ro_view9"
+DETAIL: Views containing LIMIT or OFFSET are not automatically updatable.
+HINT: To make the view updatable, provide an unconditional ON UPDATE DO INSTEAD rule or an INSTEAD OF UPDATE trigger.
+UPDATE ro_view10 SET a=a+1;
+ERROR: cannot update view "ro_view10"
+DETAIL: Views that do not select from a single table or view are not automatically updatable.
+HINT: To make the view updatable, provide an unconditional ON UPDATE DO INSTEAD rule or an INSTEAD OF UPDATE trigger.
+UPDATE ro_view11 SET a=a+1;
+ERROR: cannot update view "ro_view11"
+DETAIL: Views that do not select from a single table or view are not automatically updatable.
+HINT: To make the view updatable, provide an unconditional ON UPDATE DO INSTEAD rule or an INSTEAD OF UPDATE trigger.
+UPDATE ro_view12 SET a=a+1;
+ERROR: cannot update view "ro_view12"
+DETAIL: Views that do not select from a single table or view are not automatically updatable.
+HINT: To make the view updatable, provide an unconditional ON UPDATE DO INSTEAD rule or an INSTEAD OF UPDATE trigger.
+INSERT INTO ro_view13 VALUES (3, 'Row 3');
+ERROR: cannot insert into view "ro_view13"
+DETAIL: Views that do not select from a single table or view are not automatically updatable.
+HINT: To make the view insertable, provide an unconditional ON INSERT DO INSTEAD rule or an INSTEAD OF INSERT trigger.
+INSERT INTO ro_view14 VALUES (null);
+ERROR: cannot insert into view "ro_view14"
+DETAIL: Views that return system columns are not automatically updatable.
+HINT: To make the view insertable, provide an unconditional ON INSERT DO INSTEAD rule or an INSTEAD OF INSERT trigger.
+INSERT INTO ro_view15 VALUES (3, 'ROW 3');
+ERROR: cannot insert into view "ro_view15"
+DETAIL: Views that return columns that are not columns of their base relation are not automatically updatable.
+HINT: To make the view insertable, provide an unconditional ON INSERT DO INSTEAD rule or an INSTEAD OF INSERT trigger.
+INSERT INTO ro_view16 VALUES (3, 'Row 3', 3);
+ERROR: cannot insert into view "ro_view16"
+DETAIL: Views that return the same column more than once are not automatically updatable.
+HINT: To make the view insertable, provide an unconditional ON INSERT DO INSTEAD rule or an INSTEAD OF INSERT trigger.
+INSERT INTO ro_view17 VALUES (3, 'ROW 3');
+ERROR: cannot insert into view "ro_view1"
+DETAIL: Views containing DISTINCT are not automatically updatable.
+HINT: To make the view insertable, provide an unconditional ON INSERT DO INSTEAD rule or an INSTEAD OF INSERT trigger.
+INSERT INTO ro_view18 VALUES (3, 'ROW 3');
+ERROR: cannot insert into view "ro_view18"
+DETAIL: Security-barrier views are not automatically updatable.
+HINT: To make the view insertable, provide an unconditional ON INSERT DO INSTEAD rule or an INSTEAD OF INSERT trigger.
+DELETE FROM ro_view19;
+ERROR: cannot delete from view "ro_view19"
+DETAIL: Views that do not select from a single table or view are not automatically updatable.
+HINT: To make the view updatable, provide an unconditional ON DELETE DO INSTEAD rule or an INSTEAD OF DELETE trigger.
+UPDATE ro_view20 SET max_value=1000;
+ERROR: cannot update view "ro_view20"
+DETAIL: Views that do not select from a single table or view are not automatically updatable.
+HINT: To make the view updatable, provide an unconditional ON UPDATE DO INSTEAD rule or an INSTEAD OF UPDATE trigger.
+DROP TABLE base_tbl CASCADE;
+NOTICE: drop cascades to 16 other objects
+DETAIL: drop cascades to view ro_view1
+drop cascades to view ro_view17
+drop cascades to view ro_view2
+drop cascades to view ro_view3
+drop cascades to view ro_view5
+drop cascades to view ro_view6
+drop cascades to view ro_view7
+drop cascades to view ro_view8
+drop cascades to view ro_view9
+drop cascades to view ro_view11
+drop cascades to view ro_view13
+drop cascades to view ro_view15
+drop cascades to view ro_view16
+drop cascades to view ro_view18
+drop cascades to view ro_view4
+drop cascades to view ro_view14
+DROP VIEW ro_view10, ro_view12, ro_view19;
+DROP SEQUENCE seq CASCADE;
+NOTICE: drop cascades to view ro_view20
+-- simple updatable view
+CREATE TABLE base_tbl (a int PRIMARY KEY, b text DEFAULT 'Unspecified');
+INSERT INTO base_tbl SELECT i, 'Row ' || i FROM generate_series(-2, 2) g(i);
+CREATE VIEW rw_view1 AS SELECT * FROM base_tbl WHERE a>0;
+SELECT table_name, is_insertable_into
+ FROM information_schema.tables
+ WHERE table_name = 'rw_view1';
+ table_name | is_insertable_into
+------------+--------------------
+ rw_view1 | YES
+(1 row)
+
+SELECT table_name, is_updatable, is_insertable_into
+ FROM information_schema.views
+ WHERE table_name = 'rw_view1';
+ table_name | is_updatable | is_insertable_into
+------------+--------------+--------------------
+ rw_view1 | YES | YES
+(1 row)
+
+SELECT table_name, column_name, is_updatable
+ FROM information_schema.columns
+ WHERE table_name = 'rw_view1'
+ ORDER BY ordinal_position;
+ table_name | column_name | is_updatable
+------------+-------------+--------------
+ rw_view1 | a | YES
+ rw_view1 | b | YES
+(2 rows)
+
+INSERT INTO rw_view1 VALUES (3, 'Row 3');
+INSERT INTO rw_view1 (a) VALUES (4);
+UPDATE rw_view1 SET a=5 WHERE a=4;
+DELETE FROM rw_view1 WHERE b='Row 2';
+SELECT * FROM base_tbl;
+ a | b
+----+-------------
+ -2 | Row -2
+ -1 | Row -1
+ 0 | Row 0
+ 1 | Row 1
+ 3 | Row 3
+ 5 | Unspecified
+(6 rows)
+
+EXPLAIN (costs off) UPDATE rw_view1 SET a=6 WHERE a=5;
+ QUERY PLAN
+--------------------------------------------------
+ Update on base_tbl
+ -> Index Scan using base_tbl_pkey on base_tbl
+ Index Cond: ((a > 0) AND (a = 5))
+(3 rows)
+
+EXPLAIN (costs off) DELETE FROM rw_view1 WHERE a=5;
+ QUERY PLAN
+--------------------------------------------------
+ Delete on base_tbl
+ -> Index Scan using base_tbl_pkey on base_tbl
+ Index Cond: ((a > 0) AND (a = 5))
+(3 rows)
+
+DROP TABLE base_tbl CASCADE;
+NOTICE: drop cascades to view rw_view1
+-- view on top of view
+CREATE TABLE base_tbl (a int PRIMARY KEY, b text DEFAULT 'Unspecified');
+INSERT INTO base_tbl SELECT i, 'Row ' || i FROM generate_series(-2, 2) g(i);
+CREATE VIEW rw_view1 AS SELECT b AS bb, a AS aa FROM base_tbl WHERE a>0;
+CREATE VIEW rw_view2 AS SELECT aa AS aaa, bb AS bbb FROM rw_view1 WHERE aa<10;
+SELECT table_name, is_insertable_into
+ FROM information_schema.tables
+ WHERE table_name = 'rw_view2';
+ table_name | is_insertable_into
+------------+--------------------
+ rw_view2 | YES
+(1 row)
+
+SELECT table_name, is_updatable, is_insertable_into
+ FROM information_schema.views
+ WHERE table_name = 'rw_view2';
+ table_name | is_updatable | is_insertable_into
+------------+--------------+--------------------
+ rw_view2 | YES | YES
+(1 row)
+
+SELECT table_name, column_name, is_updatable
+ FROM information_schema.columns
+ WHERE table_name = 'rw_view2'
+ ORDER BY ordinal_position;
+ table_name | column_name | is_updatable
+------------+-------------+--------------
+ rw_view2 | aaa | YES
+ rw_view2 | bbb | YES
+(2 rows)
+
+INSERT INTO rw_view2 VALUES (3, 'Row 3');
+INSERT INTO rw_view2 (aaa) VALUES (4);
+SELECT * FROM rw_view2;
+ aaa | bbb
+-----+-------------
+ 1 | Row 1
+ 2 | Row 2
+ 3 | Row 3
+ 4 | Unspecified
+(4 rows)
+
+UPDATE rw_view2 SET bbb='Row 4' WHERE aaa=4;
+DELETE FROM rw_view2 WHERE aaa=2;
+SELECT * FROM rw_view2;
+ aaa | bbb
+-----+-------
+ 1 | Row 1
+ 3 | Row 3
+ 4 | Row 4
+(3 rows)
+
+EXPLAIN (costs off) UPDATE rw_view2 SET aaa=5 WHERE aaa=4;
+ QUERY PLAN
+--------------------------------------------------------
+ Update on base_tbl
+ -> Index Scan using base_tbl_pkey on base_tbl
+ Index Cond: ((a < 10) AND (a > 0) AND (a = 4))
+(3 rows)
+
+EXPLAIN (costs off) DELETE FROM rw_view2 WHERE aaa=4;
+ QUERY PLAN
+--------------------------------------------------------
+ Delete on base_tbl
+ -> Index Scan using base_tbl_pkey on base_tbl
+ Index Cond: ((a < 10) AND (a > 0) AND (a = 4))
+(3 rows)
+
+DROP TABLE base_tbl CASCADE;
+NOTICE: drop cascades to 2 other objects
+DETAIL: drop cascades to view rw_view1
+drop cascades to view rw_view2
+-- view on top of view with rules
+CREATE TABLE base_tbl (a int PRIMARY KEY, b text DEFAULT 'Unspecified');
+INSERT INTO base_tbl SELECT i, 'Row ' || i FROM generate_series(-2, 2) g(i);
+CREATE VIEW rw_view1 AS SELECT * FROM base_tbl WHERE a>0 OFFSET 0; -- not updatable without rules/triggers
+CREATE VIEW rw_view2 AS SELECT * FROM rw_view1 WHERE a<10;
+SELECT table_name, is_insertable_into
+ FROM information_schema.tables
+ WHERE table_name LIKE 'rw_view%'
+ ORDER BY table_name;
+ table_name | is_insertable_into
+------------+--------------------
+ rw_view1 | NO
+ rw_view2 | NO
+(2 rows)
+
+SELECT table_name, is_updatable, is_insertable_into
+ FROM information_schema.views
+ WHERE table_name LIKE 'rw_view%'
+ ORDER BY table_name;
+ table_name | is_updatable | is_insertable_into
+------------+--------------+--------------------
+ rw_view1 | NO | NO
+ rw_view2 | NO | NO
+(2 rows)
+
+SELECT table_name, column_name, is_updatable
+ FROM information_schema.columns
+ WHERE table_name LIKE 'rw_view%'
+ ORDER BY table_name, ordinal_position;
+ table_name | column_name | is_updatable
+------------+-------------+--------------
+ rw_view1 | a | NO
+ rw_view1 | b | NO
+ rw_view2 | a | NO
+ rw_view2 | b | NO
+(4 rows)
+
+CREATE RULE rw_view1_ins_rule AS ON INSERT TO rw_view1
+ DO INSTEAD INSERT INTO base_tbl VALUES (NEW.a, NEW.b) RETURNING *;
+SELECT table_name, is_insertable_into
+ FROM information_schema.tables
+ WHERE table_name LIKE 'rw_view%'
+ ORDER BY table_name;
+ table_name | is_insertable_into
+------------+--------------------
+ rw_view1 | YES
+ rw_view2 | YES
+(2 rows)
+
+SELECT table_name, is_updatable, is_insertable_into
+ FROM information_schema.views
+ WHERE table_name LIKE 'rw_view%'
+ ORDER BY table_name;
+ table_name | is_updatable | is_insertable_into
+------------+--------------+--------------------
+ rw_view1 | NO | YES
+ rw_view2 | NO | YES
+(2 rows)
+
+SELECT table_name, column_name, is_updatable
+ FROM information_schema.columns
+ WHERE table_name LIKE 'rw_view%'
+ ORDER BY table_name, ordinal_position;
+ table_name | column_name | is_updatable
+------------+-------------+--------------
+ rw_view1 | a | NO
+ rw_view1 | b | NO
+ rw_view2 | a | NO
+ rw_view2 | b | NO
+(4 rows)
+
+CREATE RULE rw_view1_upd_rule AS ON UPDATE TO rw_view1
+ DO INSTEAD UPDATE base_tbl SET b=NEW.b WHERE a=OLD.a RETURNING NEW.*;
+SELECT table_name, is_insertable_into
+ FROM information_schema.tables
+ WHERE table_name LIKE 'rw_view%'
+ ORDER BY table_name;
+ table_name | is_insertable_into
+------------+--------------------
+ rw_view1 | YES
+ rw_view2 | YES
+(2 rows)
+
+SELECT table_name, is_updatable, is_insertable_into
+ FROM information_schema.views
+ WHERE table_name LIKE 'rw_view%'
+ ORDER BY table_name;
+ table_name | is_updatable | is_insertable_into
+------------+--------------+--------------------
+ rw_view1 | NO | YES
+ rw_view2 | NO | YES
+(2 rows)
+
+SELECT table_name, column_name, is_updatable
+ FROM information_schema.columns
+ WHERE table_name LIKE 'rw_view%'
+ ORDER BY table_name, ordinal_position;
+ table_name | column_name | is_updatable
+------------+-------------+--------------
+ rw_view1 | a | NO
+ rw_view1 | b | NO
+ rw_view2 | a | NO
+ rw_view2 | b | NO
+(4 rows)
+
+CREATE RULE rw_view1_del_rule AS ON DELETE TO rw_view1
+ DO INSTEAD DELETE FROM base_tbl WHERE a=OLD.a RETURNING OLD.*;
+SELECT table_name, is_insertable_into
+ FROM information_schema.tables
+ WHERE table_name LIKE 'rw_view%'
+ ORDER BY table_name;
+ table_name | is_insertable_into
+------------+--------------------
+ rw_view1 | YES
+ rw_view2 | YES
+(2 rows)
+
+SELECT table_name, is_updatable, is_insertable_into
+ FROM information_schema.views
+ WHERE table_name LIKE 'rw_view%'
+ ORDER BY table_name;
+ table_name | is_updatable | is_insertable_into
+------------+--------------+--------------------
+ rw_view1 | YES | YES
+ rw_view2 | YES | YES
+(2 rows)
+
+SELECT table_name, column_name, is_updatable
+ FROM information_schema.columns
+ WHERE table_name LIKE 'rw_view%'
+ ORDER BY table_name, ordinal_position;
+ table_name | column_name | is_updatable
+------------+-------------+--------------
+ rw_view1 | a | YES
+ rw_view1 | b | YES
+ rw_view2 | a | YES
+ rw_view2 | b | YES
+(4 rows)
+
+INSERT INTO rw_view2 VALUES (3, 'Row 3') RETURNING *;
+ a | b
+---+-------
+ 3 | Row 3
+(1 row)
+
+UPDATE rw_view2 SET b='Row three' WHERE a=3 RETURNING *;
+ a | b
+---+-----------
+ 3 | Row three
+(1 row)
+
+SELECT * FROM rw_view2;
+ a | b
+---+-----------
+ 1 | Row 1
+ 2 | Row 2
+ 3 | Row three
+(3 rows)
+
+DELETE FROM rw_view2 WHERE a=3 RETURNING *;
+ a | b
+---+-----------
+ 3 | Row three
+(1 row)
+
+SELECT * FROM rw_view2;
+ a | b
+---+-------
+ 1 | Row 1
+ 2 | Row 2
+(2 rows)
+
+EXPLAIN (costs off) UPDATE rw_view2 SET a=3 WHERE a=2;
+ QUERY PLAN
+------------------------------------------------------------------
+ Update on base_tbl
+ -> Nested Loop
+ -> Index Scan using base_tbl_pkey on base_tbl
+ Index Cond: (a = 2)
+ -> Subquery Scan on rw_view1
+ Filter: ((rw_view1.a < 10) AND (rw_view1.a = 2))
+ -> Limit
+ -> Bitmap Heap Scan on base_tbl base_tbl_1
+ Recheck Cond: (a > 0)
+ -> Bitmap Index Scan on base_tbl_pkey
+ Index Cond: (a > 0)
+(11 rows)
+
+EXPLAIN (costs off) DELETE FROM rw_view2 WHERE a=2;
+ QUERY PLAN
+------------------------------------------------------------------
+ Delete on base_tbl
+ -> Nested Loop
+ -> Index Scan using base_tbl_pkey on base_tbl
+ Index Cond: (a = 2)
+ -> Subquery Scan on rw_view1
+ Filter: ((rw_view1.a < 10) AND (rw_view1.a = 2))
+ -> Limit
+ -> Bitmap Heap Scan on base_tbl base_tbl_1
+ Recheck Cond: (a > 0)
+ -> Bitmap Index Scan on base_tbl_pkey
+ Index Cond: (a > 0)
+(11 rows)
+
+DROP TABLE base_tbl CASCADE;
+NOTICE: drop cascades to 2 other objects
+DETAIL: drop cascades to view rw_view1
+drop cascades to view rw_view2
+-- view on top of view with triggers
+CREATE TABLE base_tbl (a int PRIMARY KEY, b text DEFAULT 'Unspecified');
+INSERT INTO base_tbl SELECT i, 'Row ' || i FROM generate_series(-2, 2) g(i);
+CREATE VIEW rw_view1 AS SELECT * FROM base_tbl WHERE a>0 OFFSET 0; -- not updatable without rules/triggers
+CREATE VIEW rw_view2 AS SELECT * FROM rw_view1 WHERE a<10;
+SELECT table_name, is_insertable_into
+ FROM information_schema.tables
+ WHERE table_name LIKE 'rw_view%'
+ ORDER BY table_name;
+ table_name | is_insertable_into
+------------+--------------------
+ rw_view1 | NO
+ rw_view2 | NO
+(2 rows)
+
+SELECT table_name, is_updatable, is_insertable_into,
+ is_trigger_updatable, is_trigger_deletable,
+ is_trigger_insertable_into
+ FROM information_schema.views
+ WHERE table_name LIKE 'rw_view%'
+ ORDER BY table_name;
+ table_name | is_updatable | is_insertable_into | is_trigger_updatable | is_trigger_deletable | is_trigger_insertable_into
+------------+--------------+--------------------+----------------------+----------------------+----------------------------
+ rw_view1 | NO | NO | NO | NO | NO
+ rw_view2 | NO | NO | NO | NO | NO
+(2 rows)
+
+SELECT table_name, column_name, is_updatable
+ FROM information_schema.columns
+ WHERE table_name LIKE 'rw_view%'
+ ORDER BY table_name, ordinal_position;
+ table_name | column_name | is_updatable
+------------+-------------+--------------
+ rw_view1 | a | NO
+ rw_view1 | b | NO
+ rw_view2 | a | NO
+ rw_view2 | b | NO
+(4 rows)
+
+CREATE FUNCTION rw_view1_trig_fn()
+RETURNS trigger AS
+$$
+BEGIN
+ IF TG_OP = 'INSERT' THEN
+ INSERT INTO base_tbl VALUES (NEW.a, NEW.b);
+ RETURN NEW;
+ ELSIF TG_OP = 'UPDATE' THEN
+ UPDATE base_tbl SET b=NEW.b WHERE a=OLD.a;
+ RETURN NEW;
+ ELSIF TG_OP = 'DELETE' THEN
+ DELETE FROM base_tbl WHERE a=OLD.a;
+ RETURN OLD;
+ END IF;
+END;
+$$
+LANGUAGE plpgsql;
+CREATE TRIGGER rw_view1_ins_trig INSTEAD OF INSERT ON rw_view1
+ FOR EACH ROW EXECUTE PROCEDURE rw_view1_trig_fn();
+SELECT table_name, is_insertable_into
+ FROM information_schema.tables
+ WHERE table_name LIKE 'rw_view%'
+ ORDER BY table_name;
+ table_name | is_insertable_into
+------------+--------------------
+ rw_view1 | NO
+ rw_view2 | NO
+(2 rows)
+
+SELECT table_name, is_updatable, is_insertable_into,
+ is_trigger_updatable, is_trigger_deletable,
+ is_trigger_insertable_into
+ FROM information_schema.views
+ WHERE table_name LIKE 'rw_view%'
+ ORDER BY table_name;
+ table_name | is_updatable | is_insertable_into | is_trigger_updatable | is_trigger_deletable | is_trigger_insertable_into
+------------+--------------+--------------------+----------------------+----------------------+----------------------------
+ rw_view1 | NO | NO | NO | NO | YES
+ rw_view2 | NO | NO | NO | NO | NO
+(2 rows)
+
+SELECT table_name, column_name, is_updatable
+ FROM information_schema.columns
+ WHERE table_name LIKE 'rw_view%'
+ ORDER BY table_name, ordinal_position;
+ table_name | column_name | is_updatable
+------------+-------------+--------------
+ rw_view1 | a | NO
+ rw_view1 | b | NO
+ rw_view2 | a | NO
+ rw_view2 | b | NO
+(4 rows)
+
+CREATE TRIGGER rw_view1_upd_trig INSTEAD OF UPDATE ON rw_view1
+ FOR EACH ROW EXECUTE PROCEDURE rw_view1_trig_fn();
+SELECT table_name, is_insertable_into
+ FROM information_schema.tables
+ WHERE table_name LIKE 'rw_view%'
+ ORDER BY table_name;
+ table_name | is_insertable_into
+------------+--------------------
+ rw_view1 | NO
+ rw_view2 | NO
+(2 rows)
+
+SELECT table_name, is_updatable, is_insertable_into,
+ is_trigger_updatable, is_trigger_deletable,
+ is_trigger_insertable_into
+ FROM information_schema.views
+ WHERE table_name LIKE 'rw_view%'
+ ORDER BY table_name;
+ table_name | is_updatable | is_insertable_into | is_trigger_updatable | is_trigger_deletable | is_trigger_insertable_into
+------------+--------------+--------------------+----------------------+----------------------+----------------------------
+ rw_view1 | NO | NO | YES | NO | YES
+ rw_view2 | NO | NO | NO | NO | NO
+(2 rows)
+
+SELECT table_name, column_name, is_updatable
+ FROM information_schema.columns
+ WHERE table_name LIKE 'rw_view%'
+ ORDER BY table_name, ordinal_position;
+ table_name | column_name | is_updatable
+------------+-------------+--------------
+ rw_view1 | a | NO
+ rw_view1 | b | NO
+ rw_view2 | a | NO
+ rw_view2 | b | NO
+(4 rows)
+
+CREATE TRIGGER rw_view1_del_trig INSTEAD OF DELETE ON rw_view1
+ FOR EACH ROW EXECUTE PROCEDURE rw_view1_trig_fn();
+SELECT table_name, is_insertable_into
+ FROM information_schema.tables
+ WHERE table_name LIKE 'rw_view%'
+ ORDER BY table_name;
+ table_name | is_insertable_into
+------------+--------------------
+ rw_view1 | NO
+ rw_view2 | NO
+(2 rows)
+
+SELECT table_name, is_updatable, is_insertable_into,
+ is_trigger_updatable, is_trigger_deletable,
+ is_trigger_insertable_into
+ FROM information_schema.views
+ WHERE table_name LIKE 'rw_view%'
+ ORDER BY table_name;
+ table_name | is_updatable | is_insertable_into | is_trigger_updatable | is_trigger_deletable | is_trigger_insertable_into
+------------+--------------+--------------------+----------------------+----------------------+----------------------------
+ rw_view1 | NO | NO | YES | YES | YES
+ rw_view2 | NO | NO | NO | NO | NO
+(2 rows)
+
+SELECT table_name, column_name, is_updatable
+ FROM information_schema.columns
+ WHERE table_name LIKE 'rw_view%'
+ ORDER BY table_name, ordinal_position;
+ table_name | column_name | is_updatable
+------------+-------------+--------------
+ rw_view1 | a | NO
+ rw_view1 | b | NO
+ rw_view2 | a | NO
+ rw_view2 | b | NO
+(4 rows)
+
+INSERT INTO rw_view2 VALUES (3, 'Row 3') RETURNING *;
+ a | b
+---+-------
+ 3 | Row 3
+(1 row)
+
+UPDATE rw_view2 SET b='Row three' WHERE a=3 RETURNING *;
+ a | b
+---+-----------
+ 3 | Row three
+(1 row)
+
+SELECT * FROM rw_view2;
+ a | b
+---+-----------
+ 1 | Row 1
+ 2 | Row 2
+ 3 | Row three
+(3 rows)
+
+DELETE FROM rw_view2 WHERE a=3 RETURNING *;
+ a | b
+---+-----------
+ 3 | Row three
+(1 row)
+
+SELECT * FROM rw_view2;
+ a | b
+---+-------
+ 1 | Row 1
+ 2 | Row 2
+(2 rows)
+
+EXPLAIN (costs off) UPDATE rw_view2 SET a=3 WHERE a=2;
+ QUERY PLAN
+------------------------------------------------------------
+ Update on rw_view1 rw_view1_1
+ -> Subquery Scan on rw_view1
+ Filter: ((rw_view1.a < 10) AND (rw_view1.a = 2))
+ -> Limit
+ -> Bitmap Heap Scan on base_tbl
+ Recheck Cond: (a > 0)
+ -> Bitmap Index Scan on base_tbl_pkey
+ Index Cond: (a > 0)
+(8 rows)
+
+EXPLAIN (costs off) DELETE FROM rw_view2 WHERE a=2;
+ QUERY PLAN
+------------------------------------------------------------
+ Delete on rw_view1 rw_view1_1
+ -> Subquery Scan on rw_view1
+ Filter: ((rw_view1.a < 10) AND (rw_view1.a = 2))
+ -> Limit
+ -> Bitmap Heap Scan on base_tbl
+ Recheck Cond: (a > 0)
+ -> Bitmap Index Scan on base_tbl_pkey
+ Index Cond: (a > 0)
+(8 rows)
+
+DROP TABLE base_tbl CASCADE;
+NOTICE: drop cascades to 2 other objects
+DETAIL: drop cascades to view rw_view1
+drop cascades to view rw_view2
+DROP FUNCTION rw_view1_trig_fn();
+-- update using whole row from view
+CREATE TABLE base_tbl (a int PRIMARY KEY, b text DEFAULT 'Unspecified');
+INSERT INTO base_tbl SELECT i, 'Row ' || i FROM generate_series(-2, 2) g(i);
+CREATE VIEW rw_view1 AS SELECT b AS bb, a AS aa FROM base_tbl;
+CREATE FUNCTION rw_view1_aa(x rw_view1)
+ RETURNS int AS $$ SELECT x.aa $$ LANGUAGE sql;
+UPDATE rw_view1 v SET bb='Updated row 2' WHERE rw_view1_aa(v)=2
+ RETURNING rw_view1_aa(v), v.bb;
+ rw_view1_aa | bb
+-------------+---------------
+ 2 | Updated row 2
+(1 row)
+
+SELECT * FROM base_tbl;
+ a | b
+----+---------------
+ -2 | Row -2
+ -1 | Row -1
+ 0 | Row 0
+ 1 | Row 1
+ 2 | Updated row 2
+(5 rows)
+
+EXPLAIN (costs off)
+UPDATE rw_view1 v SET bb='Updated row 2' WHERE rw_view1_aa(v)=2
+ RETURNING rw_view1_aa(v), v.bb;
+ QUERY PLAN
+--------------------------------------------------
+ Update on base_tbl
+ -> Index Scan using base_tbl_pkey on base_tbl
+ Index Cond: (a = 2)
+(3 rows)
+
+DROP TABLE base_tbl CASCADE;
+NOTICE: drop cascades to 2 other objects
+DETAIL: drop cascades to view rw_view1
+drop cascades to function rw_view1_aa(rw_view1)
+-- permissions checks
+CREATE USER view_user1;
+CREATE USER view_user2;
+SET SESSION AUTHORIZATION view_user1;
+CREATE TABLE base_tbl(a int, b text, c float);
+INSERT INTO base_tbl VALUES (1, 'Row 1', 1.0);
+CREATE VIEW rw_view1 AS SELECT b AS bb, c AS cc, a AS aa FROM base_tbl;
+INSERT INTO rw_view1 VALUES ('Row 2', 2.0, 2);
+GRANT SELECT ON base_tbl TO view_user2;
+GRANT SELECT ON rw_view1 TO view_user2;
+GRANT UPDATE (a,c) ON base_tbl TO view_user2;
+GRANT UPDATE (bb,cc) ON rw_view1 TO view_user2;
+RESET SESSION AUTHORIZATION;
+SET SESSION AUTHORIZATION view_user2;
+CREATE VIEW rw_view2 AS SELECT b AS bb, c AS cc, a AS aa FROM base_tbl;
+SELECT * FROM base_tbl; -- ok
+ a | b | c
+---+-------+---
+ 1 | Row 1 | 1
+ 2 | Row 2 | 2
+(2 rows)
+
+SELECT * FROM rw_view1; -- ok
+ bb | cc | aa
+-------+----+----
+ Row 1 | 1 | 1
+ Row 2 | 2 | 2
+(2 rows)
+
+SELECT * FROM rw_view2; -- ok
+ bb | cc | aa
+-------+----+----
+ Row 1 | 1 | 1
+ Row 2 | 2 | 2
+(2 rows)
+
+INSERT INTO base_tbl VALUES (3, 'Row 3', 3.0); -- not allowed
+ERROR: permission denied for relation base_tbl
+INSERT INTO rw_view1 VALUES ('Row 3', 3.0, 3); -- not allowed
+ERROR: permission denied for relation rw_view1
+INSERT INTO rw_view2 VALUES ('Row 3', 3.0, 3); -- not allowed
+ERROR: permission denied for relation base_tbl
+UPDATE base_tbl SET a=a, c=c; -- ok
+UPDATE base_tbl SET b=b; -- not allowed
+ERROR: permission denied for relation base_tbl
+UPDATE rw_view1 SET bb=bb, cc=cc; -- ok
+UPDATE rw_view1 SET aa=aa; -- not allowed
+ERROR: permission denied for relation rw_view1
+UPDATE rw_view2 SET aa=aa, cc=cc; -- ok
+UPDATE rw_view2 SET bb=bb; -- not allowed
+ERROR: permission denied for relation base_tbl
+DELETE FROM base_tbl; -- not allowed
+ERROR: permission denied for relation base_tbl
+DELETE FROM rw_view1; -- not allowed
+ERROR: permission denied for relation rw_view1
+DELETE FROM rw_view2; -- not allowed
+ERROR: permission denied for relation base_tbl
+RESET SESSION AUTHORIZATION;
+SET SESSION AUTHORIZATION view_user1;
+GRANT INSERT, DELETE ON base_tbl TO view_user2;
+RESET SESSION AUTHORIZATION;
+SET SESSION AUTHORIZATION view_user2;
+INSERT INTO base_tbl VALUES (3, 'Row 3', 3.0); -- ok
+INSERT INTO rw_view1 VALUES ('Row 4', 4.0, 4); -- not allowed
+ERROR: permission denied for relation rw_view1
+INSERT INTO rw_view2 VALUES ('Row 4', 4.0, 4); -- ok
+DELETE FROM base_tbl WHERE a=1; -- ok
+DELETE FROM rw_view1 WHERE aa=2; -- not allowed
+ERROR: permission denied for relation rw_view1
+DELETE FROM rw_view2 WHERE aa=2; -- ok
+SELECT * FROM base_tbl;
+ a | b | c
+---+-------+---
+ 3 | Row 3 | 3
+ 4 | Row 4 | 4
+(2 rows)
+
+RESET SESSION AUTHORIZATION;
+SET SESSION AUTHORIZATION view_user1;
+REVOKE INSERT, DELETE ON base_tbl FROM view_user2;
+GRANT INSERT, DELETE ON rw_view1 TO view_user2;
+RESET SESSION AUTHORIZATION;
+SET SESSION AUTHORIZATION view_user2;
+INSERT INTO base_tbl VALUES (5, 'Row 5', 5.0); -- not allowed
+ERROR: permission denied for relation base_tbl
+INSERT INTO rw_view1 VALUES ('Row 5', 5.0, 5); -- ok
+INSERT INTO rw_view2 VALUES ('Row 6', 6.0, 6); -- not allowed
+ERROR: permission denied for relation base_tbl
+DELETE FROM base_tbl WHERE a=3; -- not allowed
+ERROR: permission denied for relation base_tbl
+DELETE FROM rw_view1 WHERE aa=3; -- ok
+DELETE FROM rw_view2 WHERE aa=4; -- not allowed
+ERROR: permission denied for relation base_tbl
+SELECT * FROM base_tbl;
+ a | b | c
+---+-------+---
+ 4 | Row 4 | 4
+ 5 | Row 5 | 5
+(2 rows)
+
+RESET SESSION AUTHORIZATION;
+DROP TABLE base_tbl CASCADE;
+NOTICE: drop cascades to 2 other objects
+DETAIL: drop cascades to view rw_view1
+drop cascades to view rw_view2
+DROP USER view_user1;
+DROP USER view_user2;
+-- column defaults
+CREATE TABLE base_tbl (a int PRIMARY KEY, b text DEFAULT 'Unspecified', c serial);
+INSERT INTO base_tbl VALUES (1, 'Row 1');
+INSERT INTO base_tbl VALUES (2, 'Row 2');
+INSERT INTO base_tbl VALUES (3);
+CREATE VIEW rw_view1 AS SELECT a AS aa, b AS bb FROM base_tbl;
+ALTER VIEW rw_view1 ALTER COLUMN bb SET DEFAULT 'View default';
+INSERT INTO rw_view1 VALUES (4, 'Row 4');
+INSERT INTO rw_view1 (aa) VALUES (5);
+SELECT * FROM base_tbl;
+ a | b | c
+---+--------------+---
+ 1 | Row 1 | 1
+ 2 | Row 2 | 2
+ 3 | Unspecified | 3
+ 4 | Row 4 | 4
+ 5 | View default | 5
+(5 rows)
+
+DROP TABLE base_tbl CASCADE;
+NOTICE: drop cascades to view rw_view1
+-- Table having triggers
+CREATE TABLE base_tbl (a int PRIMARY KEY, b text DEFAULT 'Unspecified');
+INSERT INTO base_tbl VALUES (1, 'Row 1');
+INSERT INTO base_tbl VALUES (2, 'Row 2');
+CREATE FUNCTION rw_view1_trig_fn()
+RETURNS trigger AS
+$$
+BEGIN
+ IF TG_OP = 'INSERT' THEN
+ UPDATE base_tbl SET b=NEW.b WHERE a=1;
+ RETURN NULL;
+ END IF;
+ RETURN NULL;
+END;
+$$
+LANGUAGE plpgsql;
+CREATE TRIGGER rw_view1_ins_trig AFTER INSERT ON base_tbl
+ FOR EACH ROW EXECUTE PROCEDURE rw_view1_trig_fn();
+CREATE VIEW rw_view1 AS SELECT a AS aa, b AS bb FROM base_tbl;
+INSERT INTO rw_view1 VALUES (3, 'Row 3');
+select * from base_tbl;
+ a | b
+---+-------
+ 2 | Row 2
+ 3 | Row 3
+ 1 | Row 3
+(3 rows)
+
+DROP VIEW rw_view1;
+DROP TRIGGER rw_view1_ins_trig on base_tbl;
+DROP FUNCTION rw_view1_trig_fn();
+DROP TABLE base_tbl;
+-- view with ORDER BY
+CREATE TABLE base_tbl (a int, b int);
+INSERT INTO base_tbl VALUES (1,2), (4,5), (3,-3);
+CREATE VIEW rw_view1 AS SELECT * FROM base_tbl ORDER BY a+b;
+SELECT * FROM rw_view1;
+ a | b
+---+----
+ 3 | -3
+ 1 | 2
+ 4 | 5
+(3 rows)
+
+INSERT INTO rw_view1 VALUES (7,-8);
+SELECT * FROM rw_view1;
+ a | b
+---+----
+ 7 | -8
+ 3 | -3
+ 1 | 2
+ 4 | 5
+(4 rows)
+
+EXPLAIN (verbose, costs off) UPDATE rw_view1 SET b = b + 1 RETURNING *;
+ QUERY PLAN
+-------------------------------------------------------------
+ Update on public.base_tbl
+ Output: base_tbl.a, base_tbl.b
+ -> Seq Scan on public.base_tbl
+ Output: base_tbl.a, (base_tbl.b + 1), base_tbl.ctid
+(4 rows)
+
+UPDATE rw_view1 SET b = b + 1 RETURNING *;
+ a | b
+---+----
+ 1 | 3
+ 4 | 6
+ 3 | -2
+ 7 | -7
+(4 rows)
+
+SELECT * FROM rw_view1;
+ a | b
+---+----
+ 7 | -7
+ 3 | -2
+ 1 | 3
+ 4 | 6
+(4 rows)
+
+DROP TABLE base_tbl CASCADE;
+NOTICE: drop cascades to view rw_view1
+-- multiple array-column updates
+CREATE TABLE base_tbl (a int, arr int[]);
+INSERT INTO base_tbl VALUES (1,ARRAY[2]), (3,ARRAY[4]);
+CREATE VIEW rw_view1 AS SELECT * FROM base_tbl;
+UPDATE rw_view1 SET arr[1] = 42, arr[2] = 77 WHERE a = 3;
+SELECT * FROM rw_view1;
+ a | arr
+---+---------
+ 1 | {2}
+ 3 | {42,77}
+(2 rows)
+
+DROP TABLE base_tbl CASCADE;
+NOTICE: drop cascades to view rw_view1
# ----------
# Another group of parallel tests
# ----------
-test: create_aggregate create_function_3 create_cast constraints triggers inherit create_table_like typed_table vacuum drop_if_exists
+test: create_aggregate create_function_3 create_cast constraints triggers inherit create_table_like typed_table vacuum drop_if_exists updatable_views
# ----------
# sanity_check does a vacuum, affecting the sort order of SELECT *
test: typed_table
test: vacuum
test: drop_if_exists
+test: updatable_views
test: sanity_check
test: errors
test: select
CREATE VIEW main_view AS SELECT a, b FROM main_table;
--- Updates should fail without rules or triggers
-INSERT INTO main_view VALUES (1,2);
-UPDATE main_view SET b = 20 WHERE a = 50;
-DELETE FROM main_view WHERE a = 50;
--- Should fail even when there are no matching rows
-DELETE FROM main_view WHERE a = 51;
-
-- VIEW trigger function
CREATE OR REPLACE FUNCTION view_trigger() RETURNS trigger
LANGUAGE plpgsql AS $$
--- /dev/null
+--
+-- UPDATABLE VIEWS
+--
+
+-- check that non-updatable views are rejected with useful error messages
+
+CREATE TABLE base_tbl (a int PRIMARY KEY, b text DEFAULT 'Unspecified');
+INSERT INTO base_tbl SELECT i, 'Row ' || i FROM generate_series(-2, 2) g(i);
+
+CREATE VIEW ro_view1 AS SELECT DISTINCT a, b FROM base_tbl; -- DISTINCT not supported
+CREATE VIEW ro_view2 AS SELECT a, b FROM base_tbl GROUP BY a, b; -- GROUP BY not supported
+CREATE VIEW ro_view3 AS SELECT 1 FROM base_tbl HAVING max(a) > 0; -- HAVING not supported
+CREATE VIEW ro_view4 AS SELECT count(*) FROM base_tbl; -- Aggregate functions not supported
+CREATE VIEW ro_view5 AS SELECT a, rank() OVER() FROM base_tbl; -- Window functions not supported
+CREATE VIEW ro_view6 AS SELECT a, b FROM base_tbl UNION SELECT -a, b FROM base_tbl; -- Set ops not supported
+CREATE VIEW ro_view7 AS WITH t AS (SELECT a, b FROM base_tbl) SELECT * FROM t; -- WITH not supported
+CREATE VIEW ro_view8 AS SELECT a, b FROM base_tbl ORDER BY a OFFSET 1; -- OFFSET not supported
+CREATE VIEW ro_view9 AS SELECT a, b FROM base_tbl ORDER BY a LIMIT 1; -- LIMIT not supported
+CREATE VIEW ro_view10 AS SELECT 1 AS a; -- No base relations
+CREATE VIEW ro_view11 AS SELECT b1.a, b2.b FROM base_tbl b1, base_tbl b2; -- Multiple base relations
+CREATE VIEW ro_view12 AS SELECT * FROM generate_series(1, 10) AS g(a); -- SRF in rangetable
+CREATE VIEW ro_view13 AS SELECT a, b FROM (SELECT * FROM base_tbl) AS t; -- Subselect in rangetable
+CREATE VIEW ro_view14 AS SELECT ctid FROM base_tbl; -- System columns not supported
+CREATE VIEW ro_view15 AS SELECT a, upper(b) FROM base_tbl; -- Expression/function in targetlist
+CREATE VIEW ro_view16 AS SELECT a, b, a AS aa FROM base_tbl; -- Repeated column
+CREATE VIEW ro_view17 AS SELECT * FROM ro_view1; -- Base relation not updatable
+CREATE VIEW ro_view18 WITH (security_barrier = true)
+ AS SELECT * FROM base_tbl; -- Security barrier views not updatable
+CREATE VIEW ro_view19 AS SELECT * FROM (VALUES(1)) AS tmp(a); -- VALUES in rangetable
+CREATE SEQUENCE seq;
+CREATE VIEW ro_view20 AS SELECT * FROM seq; -- View based on a sequence
+
+SELECT table_name, is_insertable_into
+ FROM information_schema.tables
+ WHERE table_name LIKE 'ro_view%'
+ ORDER BY table_name;
+
+SELECT table_name, is_updatable, is_insertable_into
+ FROM information_schema.views
+ WHERE table_name LIKE 'ro_view%'
+ ORDER BY table_name;
+
+SELECT table_name, column_name, is_updatable
+ FROM information_schema.columns
+ WHERE table_name LIKE 'ro_view%'
+ ORDER BY table_name, ordinal_position;
+
+DELETE FROM ro_view1;
+DELETE FROM ro_view2;
+DELETE FROM ro_view3;
+DELETE FROM ro_view4;
+DELETE FROM ro_view5;
+DELETE FROM ro_view6;
+UPDATE ro_view7 SET a=a+1;
+UPDATE ro_view8 SET a=a+1;
+UPDATE ro_view9 SET a=a+1;
+UPDATE ro_view10 SET a=a+1;
+UPDATE ro_view11 SET a=a+1;
+UPDATE ro_view12 SET a=a+1;
+INSERT INTO ro_view13 VALUES (3, 'Row 3');
+INSERT INTO ro_view14 VALUES (null);
+INSERT INTO ro_view15 VALUES (3, 'ROW 3');
+INSERT INTO ro_view16 VALUES (3, 'Row 3', 3);
+INSERT INTO ro_view17 VALUES (3, 'ROW 3');
+INSERT INTO ro_view18 VALUES (3, 'ROW 3');
+DELETE FROM ro_view19;
+UPDATE ro_view20 SET max_value=1000;
+
+DROP TABLE base_tbl CASCADE;
+DROP VIEW ro_view10, ro_view12, ro_view19;
+DROP SEQUENCE seq CASCADE;
+
+-- simple updatable view
+
+CREATE TABLE base_tbl (a int PRIMARY KEY, b text DEFAULT 'Unspecified');
+INSERT INTO base_tbl SELECT i, 'Row ' || i FROM generate_series(-2, 2) g(i);
+
+CREATE VIEW rw_view1 AS SELECT * FROM base_tbl WHERE a>0;
+
+SELECT table_name, is_insertable_into
+ FROM information_schema.tables
+ WHERE table_name = 'rw_view1';
+
+SELECT table_name, is_updatable, is_insertable_into
+ FROM information_schema.views
+ WHERE table_name = 'rw_view1';
+
+SELECT table_name, column_name, is_updatable
+ FROM information_schema.columns
+ WHERE table_name = 'rw_view1'
+ ORDER BY ordinal_position;
+
+INSERT INTO rw_view1 VALUES (3, 'Row 3');
+INSERT INTO rw_view1 (a) VALUES (4);
+UPDATE rw_view1 SET a=5 WHERE a=4;
+DELETE FROM rw_view1 WHERE b='Row 2';
+SELECT * FROM base_tbl;
+
+EXPLAIN (costs off) UPDATE rw_view1 SET a=6 WHERE a=5;
+EXPLAIN (costs off) DELETE FROM rw_view1 WHERE a=5;
+
+DROP TABLE base_tbl CASCADE;
+
+-- view on top of view
+
+CREATE TABLE base_tbl (a int PRIMARY KEY, b text DEFAULT 'Unspecified');
+INSERT INTO base_tbl SELECT i, 'Row ' || i FROM generate_series(-2, 2) g(i);
+
+CREATE VIEW rw_view1 AS SELECT b AS bb, a AS aa FROM base_tbl WHERE a>0;
+CREATE VIEW rw_view2 AS SELECT aa AS aaa, bb AS bbb FROM rw_view1 WHERE aa<10;
+
+SELECT table_name, is_insertable_into
+ FROM information_schema.tables
+ WHERE table_name = 'rw_view2';
+
+SELECT table_name, is_updatable, is_insertable_into
+ FROM information_schema.views
+ WHERE table_name = 'rw_view2';
+
+SELECT table_name, column_name, is_updatable
+ FROM information_schema.columns
+ WHERE table_name = 'rw_view2'
+ ORDER BY ordinal_position;
+
+INSERT INTO rw_view2 VALUES (3, 'Row 3');
+INSERT INTO rw_view2 (aaa) VALUES (4);
+SELECT * FROM rw_view2;
+UPDATE rw_view2 SET bbb='Row 4' WHERE aaa=4;
+DELETE FROM rw_view2 WHERE aaa=2;
+SELECT * FROM rw_view2;
+
+EXPLAIN (costs off) UPDATE rw_view2 SET aaa=5 WHERE aaa=4;
+EXPLAIN (costs off) DELETE FROM rw_view2 WHERE aaa=4;
+
+DROP TABLE base_tbl CASCADE;
+
+-- view on top of view with rules
+
+CREATE TABLE base_tbl (a int PRIMARY KEY, b text DEFAULT 'Unspecified');
+INSERT INTO base_tbl SELECT i, 'Row ' || i FROM generate_series(-2, 2) g(i);
+
+CREATE VIEW rw_view1 AS SELECT * FROM base_tbl WHERE a>0 OFFSET 0; -- not updatable without rules/triggers
+CREATE VIEW rw_view2 AS SELECT * FROM rw_view1 WHERE a<10;
+
+SELECT table_name, is_insertable_into
+ FROM information_schema.tables
+ WHERE table_name LIKE 'rw_view%'
+ ORDER BY table_name;
+
+SELECT table_name, is_updatable, is_insertable_into
+ FROM information_schema.views
+ WHERE table_name LIKE 'rw_view%'
+ ORDER BY table_name;
+
+SELECT table_name, column_name, is_updatable
+ FROM information_schema.columns
+ WHERE table_name LIKE 'rw_view%'
+ ORDER BY table_name, ordinal_position;
+
+CREATE RULE rw_view1_ins_rule AS ON INSERT TO rw_view1
+ DO INSTEAD INSERT INTO base_tbl VALUES (NEW.a, NEW.b) RETURNING *;
+
+SELECT table_name, is_insertable_into
+ FROM information_schema.tables
+ WHERE table_name LIKE 'rw_view%'
+ ORDER BY table_name;
+
+SELECT table_name, is_updatable, is_insertable_into
+ FROM information_schema.views
+ WHERE table_name LIKE 'rw_view%'
+ ORDER BY table_name;
+
+SELECT table_name, column_name, is_updatable
+ FROM information_schema.columns
+ WHERE table_name LIKE 'rw_view%'
+ ORDER BY table_name, ordinal_position;
+
+CREATE RULE rw_view1_upd_rule AS ON UPDATE TO rw_view1
+ DO INSTEAD UPDATE base_tbl SET b=NEW.b WHERE a=OLD.a RETURNING NEW.*;
+
+SELECT table_name, is_insertable_into
+ FROM information_schema.tables
+ WHERE table_name LIKE 'rw_view%'
+ ORDER BY table_name;
+
+SELECT table_name, is_updatable, is_insertable_into
+ FROM information_schema.views
+ WHERE table_name LIKE 'rw_view%'
+ ORDER BY table_name;
+
+SELECT table_name, column_name, is_updatable
+ FROM information_schema.columns
+ WHERE table_name LIKE 'rw_view%'
+ ORDER BY table_name, ordinal_position;
+
+CREATE RULE rw_view1_del_rule AS ON DELETE TO rw_view1
+ DO INSTEAD DELETE FROM base_tbl WHERE a=OLD.a RETURNING OLD.*;
+
+SELECT table_name, is_insertable_into
+ FROM information_schema.tables
+ WHERE table_name LIKE 'rw_view%'
+ ORDER BY table_name;
+
+SELECT table_name, is_updatable, is_insertable_into
+ FROM information_schema.views
+ WHERE table_name LIKE 'rw_view%'
+ ORDER BY table_name;
+
+SELECT table_name, column_name, is_updatable
+ FROM information_schema.columns
+ WHERE table_name LIKE 'rw_view%'
+ ORDER BY table_name, ordinal_position;
+
+INSERT INTO rw_view2 VALUES (3, 'Row 3') RETURNING *;
+UPDATE rw_view2 SET b='Row three' WHERE a=3 RETURNING *;
+SELECT * FROM rw_view2;
+DELETE FROM rw_view2 WHERE a=3 RETURNING *;
+SELECT * FROM rw_view2;
+
+EXPLAIN (costs off) UPDATE rw_view2 SET a=3 WHERE a=2;
+EXPLAIN (costs off) DELETE FROM rw_view2 WHERE a=2;
+
+DROP TABLE base_tbl CASCADE;
+
+-- view on top of view with triggers
+
+CREATE TABLE base_tbl (a int PRIMARY KEY, b text DEFAULT 'Unspecified');
+INSERT INTO base_tbl SELECT i, 'Row ' || i FROM generate_series(-2, 2) g(i);
+
+CREATE VIEW rw_view1 AS SELECT * FROM base_tbl WHERE a>0 OFFSET 0; -- not updatable without rules/triggers
+CREATE VIEW rw_view2 AS SELECT * FROM rw_view1 WHERE a<10;
+
+SELECT table_name, is_insertable_into
+ FROM information_schema.tables
+ WHERE table_name LIKE 'rw_view%'
+ ORDER BY table_name;
+
+SELECT table_name, is_updatable, is_insertable_into,
+ is_trigger_updatable, is_trigger_deletable,
+ is_trigger_insertable_into
+ FROM information_schema.views
+ WHERE table_name LIKE 'rw_view%'
+ ORDER BY table_name;
+
+SELECT table_name, column_name, is_updatable
+ FROM information_schema.columns
+ WHERE table_name LIKE 'rw_view%'
+ ORDER BY table_name, ordinal_position;
+
+CREATE FUNCTION rw_view1_trig_fn()
+RETURNS trigger AS
+$$
+BEGIN
+ IF TG_OP = 'INSERT' THEN
+ INSERT INTO base_tbl VALUES (NEW.a, NEW.b);
+ RETURN NEW;
+ ELSIF TG_OP = 'UPDATE' THEN
+ UPDATE base_tbl SET b=NEW.b WHERE a=OLD.a;
+ RETURN NEW;
+ ELSIF TG_OP = 'DELETE' THEN
+ DELETE FROM base_tbl WHERE a=OLD.a;
+ RETURN OLD;
+ END IF;
+END;
+$$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER rw_view1_ins_trig INSTEAD OF INSERT ON rw_view1
+ FOR EACH ROW EXECUTE PROCEDURE rw_view1_trig_fn();
+
+SELECT table_name, is_insertable_into
+ FROM information_schema.tables
+ WHERE table_name LIKE 'rw_view%'
+ ORDER BY table_name;
+
+SELECT table_name, is_updatable, is_insertable_into,
+ is_trigger_updatable, is_trigger_deletable,
+ is_trigger_insertable_into
+ FROM information_schema.views
+ WHERE table_name LIKE 'rw_view%'
+ ORDER BY table_name;
+
+SELECT table_name, column_name, is_updatable
+ FROM information_schema.columns
+ WHERE table_name LIKE 'rw_view%'
+ ORDER BY table_name, ordinal_position;
+
+CREATE TRIGGER rw_view1_upd_trig INSTEAD OF UPDATE ON rw_view1
+ FOR EACH ROW EXECUTE PROCEDURE rw_view1_trig_fn();
+
+SELECT table_name, is_insertable_into
+ FROM information_schema.tables
+ WHERE table_name LIKE 'rw_view%'
+ ORDER BY table_name;
+
+SELECT table_name, is_updatable, is_insertable_into,
+ is_trigger_updatable, is_trigger_deletable,
+ is_trigger_insertable_into
+ FROM information_schema.views
+ WHERE table_name LIKE 'rw_view%'
+ ORDER BY table_name;
+
+SELECT table_name, column_name, is_updatable
+ FROM information_schema.columns
+ WHERE table_name LIKE 'rw_view%'
+ ORDER BY table_name, ordinal_position;
+
+CREATE TRIGGER rw_view1_del_trig INSTEAD OF DELETE ON rw_view1
+ FOR EACH ROW EXECUTE PROCEDURE rw_view1_trig_fn();
+
+SELECT table_name, is_insertable_into
+ FROM information_schema.tables
+ WHERE table_name LIKE 'rw_view%'
+ ORDER BY table_name;
+
+SELECT table_name, is_updatable, is_insertable_into,
+ is_trigger_updatable, is_trigger_deletable,
+ is_trigger_insertable_into
+ FROM information_schema.views
+ WHERE table_name LIKE 'rw_view%'
+ ORDER BY table_name;
+
+SELECT table_name, column_name, is_updatable
+ FROM information_schema.columns
+ WHERE table_name LIKE 'rw_view%'
+ ORDER BY table_name, ordinal_position;
+
+INSERT INTO rw_view2 VALUES (3, 'Row 3') RETURNING *;
+UPDATE rw_view2 SET b='Row three' WHERE a=3 RETURNING *;
+SELECT * FROM rw_view2;
+DELETE FROM rw_view2 WHERE a=3 RETURNING *;
+SELECT * FROM rw_view2;
+
+EXPLAIN (costs off) UPDATE rw_view2 SET a=3 WHERE a=2;
+EXPLAIN (costs off) DELETE FROM rw_view2 WHERE a=2;
+
+DROP TABLE base_tbl CASCADE;
+DROP FUNCTION rw_view1_trig_fn();
+
+-- update using whole row from view
+
+CREATE TABLE base_tbl (a int PRIMARY KEY, b text DEFAULT 'Unspecified');
+INSERT INTO base_tbl SELECT i, 'Row ' || i FROM generate_series(-2, 2) g(i);
+
+CREATE VIEW rw_view1 AS SELECT b AS bb, a AS aa FROM base_tbl;
+
+CREATE FUNCTION rw_view1_aa(x rw_view1)
+ RETURNS int AS $$ SELECT x.aa $$ LANGUAGE sql;
+
+UPDATE rw_view1 v SET bb='Updated row 2' WHERE rw_view1_aa(v)=2
+ RETURNING rw_view1_aa(v), v.bb;
+SELECT * FROM base_tbl;
+
+EXPLAIN (costs off)
+UPDATE rw_view1 v SET bb='Updated row 2' WHERE rw_view1_aa(v)=2
+ RETURNING rw_view1_aa(v), v.bb;
+
+DROP TABLE base_tbl CASCADE;
+
+-- permissions checks
+
+CREATE USER view_user1;
+CREATE USER view_user2;
+
+SET SESSION AUTHORIZATION view_user1;
+CREATE TABLE base_tbl(a int, b text, c float);
+INSERT INTO base_tbl VALUES (1, 'Row 1', 1.0);
+CREATE VIEW rw_view1 AS SELECT b AS bb, c AS cc, a AS aa FROM base_tbl;
+INSERT INTO rw_view1 VALUES ('Row 2', 2.0, 2);
+
+GRANT SELECT ON base_tbl TO view_user2;
+GRANT SELECT ON rw_view1 TO view_user2;
+GRANT UPDATE (a,c) ON base_tbl TO view_user2;
+GRANT UPDATE (bb,cc) ON rw_view1 TO view_user2;
+RESET SESSION AUTHORIZATION;
+
+SET SESSION AUTHORIZATION view_user2;
+CREATE VIEW rw_view2 AS SELECT b AS bb, c AS cc, a AS aa FROM base_tbl;
+SELECT * FROM base_tbl; -- ok
+SELECT * FROM rw_view1; -- ok
+SELECT * FROM rw_view2; -- ok
+
+INSERT INTO base_tbl VALUES (3, 'Row 3', 3.0); -- not allowed
+INSERT INTO rw_view1 VALUES ('Row 3', 3.0, 3); -- not allowed
+INSERT INTO rw_view2 VALUES ('Row 3', 3.0, 3); -- not allowed
+
+UPDATE base_tbl SET a=a, c=c; -- ok
+UPDATE base_tbl SET b=b; -- not allowed
+UPDATE rw_view1 SET bb=bb, cc=cc; -- ok
+UPDATE rw_view1 SET aa=aa; -- not allowed
+UPDATE rw_view2 SET aa=aa, cc=cc; -- ok
+UPDATE rw_view2 SET bb=bb; -- not allowed
+
+DELETE FROM base_tbl; -- not allowed
+DELETE FROM rw_view1; -- not allowed
+DELETE FROM rw_view2; -- not allowed
+RESET SESSION AUTHORIZATION;
+
+SET SESSION AUTHORIZATION view_user1;
+GRANT INSERT, DELETE ON base_tbl TO view_user2;
+RESET SESSION AUTHORIZATION;
+
+SET SESSION AUTHORIZATION view_user2;
+INSERT INTO base_tbl VALUES (3, 'Row 3', 3.0); -- ok
+INSERT INTO rw_view1 VALUES ('Row 4', 4.0, 4); -- not allowed
+INSERT INTO rw_view2 VALUES ('Row 4', 4.0, 4); -- ok
+DELETE FROM base_tbl WHERE a=1; -- ok
+DELETE FROM rw_view1 WHERE aa=2; -- not allowed
+DELETE FROM rw_view2 WHERE aa=2; -- ok
+SELECT * FROM base_tbl;
+RESET SESSION AUTHORIZATION;
+
+SET SESSION AUTHORIZATION view_user1;
+REVOKE INSERT, DELETE ON base_tbl FROM view_user2;
+GRANT INSERT, DELETE ON rw_view1 TO view_user2;
+RESET SESSION AUTHORIZATION;
+
+SET SESSION AUTHORIZATION view_user2;
+INSERT INTO base_tbl VALUES (5, 'Row 5', 5.0); -- not allowed
+INSERT INTO rw_view1 VALUES ('Row 5', 5.0, 5); -- ok
+INSERT INTO rw_view2 VALUES ('Row 6', 6.0, 6); -- not allowed
+DELETE FROM base_tbl WHERE a=3; -- not allowed
+DELETE FROM rw_view1 WHERE aa=3; -- ok
+DELETE FROM rw_view2 WHERE aa=4; -- not allowed
+SELECT * FROM base_tbl;
+RESET SESSION AUTHORIZATION;
+
+DROP TABLE base_tbl CASCADE;
+
+DROP USER view_user1;
+DROP USER view_user2;
+
+-- column defaults
+
+CREATE TABLE base_tbl (a int PRIMARY KEY, b text DEFAULT 'Unspecified', c serial);
+INSERT INTO base_tbl VALUES (1, 'Row 1');
+INSERT INTO base_tbl VALUES (2, 'Row 2');
+INSERT INTO base_tbl VALUES (3);
+
+CREATE VIEW rw_view1 AS SELECT a AS aa, b AS bb FROM base_tbl;
+ALTER VIEW rw_view1 ALTER COLUMN bb SET DEFAULT 'View default';
+
+INSERT INTO rw_view1 VALUES (4, 'Row 4');
+INSERT INTO rw_view1 (aa) VALUES (5);
+
+SELECT * FROM base_tbl;
+
+DROP TABLE base_tbl CASCADE;
+
+-- Table having triggers
+
+CREATE TABLE base_tbl (a int PRIMARY KEY, b text DEFAULT 'Unspecified');
+INSERT INTO base_tbl VALUES (1, 'Row 1');
+INSERT INTO base_tbl VALUES (2, 'Row 2');
+
+CREATE FUNCTION rw_view1_trig_fn()
+RETURNS trigger AS
+$$
+BEGIN
+ IF TG_OP = 'INSERT' THEN
+ UPDATE base_tbl SET b=NEW.b WHERE a=1;
+ RETURN NULL;
+ END IF;
+ RETURN NULL;
+END;
+$$
+LANGUAGE plpgsql;
+
+CREATE TRIGGER rw_view1_ins_trig AFTER INSERT ON base_tbl
+ FOR EACH ROW EXECUTE PROCEDURE rw_view1_trig_fn();
+
+CREATE VIEW rw_view1 AS SELECT a AS aa, b AS bb FROM base_tbl;
+
+INSERT INTO rw_view1 VALUES (3, 'Row 3');
+select * from base_tbl;
+
+DROP VIEW rw_view1;
+DROP TRIGGER rw_view1_ins_trig on base_tbl;
+DROP FUNCTION rw_view1_trig_fn();
+DROP TABLE base_tbl;
+
+-- view with ORDER BY
+
+CREATE TABLE base_tbl (a int, b int);
+INSERT INTO base_tbl VALUES (1,2), (4,5), (3,-3);
+
+CREATE VIEW rw_view1 AS SELECT * FROM base_tbl ORDER BY a+b;
+
+SELECT * FROM rw_view1;
+
+INSERT INTO rw_view1 VALUES (7,-8);
+SELECT * FROM rw_view1;
+
+EXPLAIN (verbose, costs off) UPDATE rw_view1 SET b = b + 1 RETURNING *;
+UPDATE rw_view1 SET b = b + 1 RETURNING *;
+SELECT * FROM rw_view1;
+
+DROP TABLE base_tbl CASCADE;
+
+-- multiple array-column updates
+
+CREATE TABLE base_tbl (a int, arr int[]);
+INSERT INTO base_tbl VALUES (1,ARRAY[2]), (3,ARRAY[4]);
+
+CREATE VIEW rw_view1 AS SELECT * FROM base_tbl;
+
+UPDATE rw_view1 SET arr[1] = 42, arr[2] = 77 WHERE a = 3;
+
+SELECT * FROM rw_view1;
+
+DROP TABLE base_tbl CASCADE;
projects / postgresql / commitdiff