* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/optimizer/prep/preptlist.c,v 1.44 2001/10/25 05:49:33 momjian Exp $
+ * $Header: /cvsroot/pgsql/src/backend/optimizer/prep/preptlist.c,v 1.45 2001/11/02 20:23:02 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#include "nodes/makefuncs.h"
#include "optimizer/prep.h"
#include "parser/parsetree.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "parser/parse_target.h"
+#include "utils/builtins.h"
#include "utils/lsyscache.h"
static TargetEntry *process_matched_tle(TargetEntry *src_tle,
TargetEntry *prior_tle,
int attrno);
+static Node *build_column_default(Relation rel, int attrno);
/*
{
new_tle = process_matched_tle(old_tle, new_tle, attrno);
tlistentry_used[old_tlist_index] = true;
+ /* keep scanning to detect multiple assignments to attr */
}
old_tlist_index++;
}
/*
* Didn't find a matching tlist entry, so make one.
*
- * For INSERT, generate a constant of the default value for the
- * attribute type, or NULL if no default value.
+ * For INSERT, generate an appropriate default value.
*
* For UPDATE, generate a Var reference to the existing value of
* the attribute, so that it gets copied to the new tuple.
*/
Oid atttype = att_tup->atttypid;
int32 atttypmod = att_tup->atttypmod;
+ Node *new_expr;
switch (command_type)
{
case CMD_INSERT:
- {
- bool hasdefault;
- Datum typedefault;
- int16 typlen;
- bool typbyval;
- Const *def_const;
-
- if (att_tup->attisset)
- {
- /*
- * Set attributes are represented as OIDs no
- * matter what the set element type is, and
- * the element type's default is irrelevant
- * too.
- */
- hasdefault = false;
- typedefault = (Datum) 0;
- typlen = sizeof(Oid);
- typbyval = true;
- }
- else
- {
-#ifdef _DROP_COLUMN_HACK__
- if (COLUMN_IS_DROPPED(att_tup))
- {
- hasdefault = false;
- typedefault = (Datum) 0;
- }
- else
-#endif /* _DROP_COLUMN_HACK__ */
- hasdefault = get_typdefault(atttype,
- &typedefault);
-
- get_typlenbyval(atttype, &typlen, &typbyval);
- }
-
- def_const = makeConst(atttype,
- typlen,
- typedefault,
- !hasdefault,
- typbyval,
- false, /* not a set */
- false);
-
- new_tle = makeTargetEntry(makeResdom(attrno,
- atttype,
- -1,
- pstrdup(attrname),
- false),
- (Node *) def_const);
- break;
- }
+ new_expr = build_column_default(rel, attrno);
+ break;
case CMD_UPDATE:
- {
- Var *temp_var;
-
#ifdef _DROP_COLUMN_HACK__
- if (COLUMN_IS_DROPPED(att_tup))
- temp_var = (Var *) makeNullConst(atttype);
- else
+ if (COLUMN_IS_DROPPED(att_tup))
+ new_expr = (Node *) makeNullConst(atttype);
+ else
#endif /* _DROP_COLUMN_HACK__ */
- temp_var = makeVar(result_relation,
- attrno,
- atttype,
- atttypmod,
- 0);
-
- new_tle = makeTargetEntry(makeResdom(attrno,
- atttype,
- atttypmod,
- pstrdup(attrname),
- false),
- (Node *) temp_var);
- break;
- }
+ new_expr = (Node *) makeVar(result_relation,
+ attrno,
+ atttype,
+ atttypmod,
+ 0);
+ break;
default:
elog(ERROR, "expand_targetlist: unexpected command_type");
+ new_expr = NULL; /* keep compiler quiet */
break;
}
+
+ new_tle = makeTargetEntry(makeResdom(attrno,
+ atttype,
+ atttypmod,
+ pstrdup(attrname),
+ false),
+ new_expr);
}
new_tlist = lappend(new_tlist, new_tle);
resdom->resno = attrno;
return makeTargetEntry(resdom, (Node *) newexpr);
}
+
+
+/*
+ * Make an expression tree for the default value for a column.
+ *
+ * This is used to fill in missing attributes in an INSERT targetlist.
+ * We look first to see if the column has a default value expression.
+ * If not, generate a constant of the default value for the attribute type,
+ * or a NULL if the type has no default value either.
+ */
+static Node *
+build_column_default(Relation rel, int attrno)
+{
+ TupleDesc rd_att = rel->rd_att;
+ Form_pg_attribute att_tup = rd_att->attrs[attrno - 1];
+ Oid atttype = att_tup->atttypid;
+ int32 atttypmod = att_tup->atttypmod;
+ bool hasdefault;
+ Datum typedefault;
+ int16 typlen;
+ bool typbyval;
+ Node *expr;
+
+ /*
+ * Scan to see if relation has a default for this column.
+ */
+ if (rd_att->constr && rd_att->constr->num_defval > 0)
+ {
+ AttrDefault *defval = rd_att->constr->defval;
+ int ndef = rd_att->constr->num_defval;
+
+ while (--ndef >= 0)
+ {
+ if (attrno == defval[ndef].adnum)
+ {
+ Oid type_id;
+
+ /*
+ * Found it, convert string representation to node tree.
+ */
+ expr = stringToNode(defval[ndef].adbin);
+
+ /*
+ * Make sure the value is coerced to the target column type
+ * (might not be right type yet if it's not a constant!)
+ * This should match the parser's processing of non-defaulted
+ * expressions --- see updateTargetListEntry().
+ */
+ type_id = exprType(expr);
+
+ if (type_id != atttype)
+ {
+ expr = CoerceTargetExpr(NULL, expr, type_id,
+ atttype, atttypmod);
+ /*
+ * This really shouldn't fail; should have checked the
+ * default's type when it was created ...
+ */
+ if (expr == NULL)
+ elog(ERROR, "Column \"%s\" is of type %s"
+ " but default expression is of type %s"
+ "\n\tYou will need to rewrite or cast the expression",
+ NameStr(att_tup->attname),
+ format_type_be(atttype),
+ format_type_be(type_id));
+ }
+
+ /*
+ * If the column is a fixed-length type, it may need a
+ * length coercion as well as a type coercion.
+ */
+ expr = coerce_type_typmod(NULL, expr,
+ atttype, atttypmod);
+ return expr;
+ }
+ }
+ }
+
+ /*
+ * No per-column default, so look for a default for the type itself.
+ * If there isn't one, we generate a NULL constant of the correct type.
+ */
+ if (att_tup->attisset)
+ {
+ /*
+ * Set attributes are represented as OIDs no matter what the set
+ * element type is, and the element type's default is irrelevant too.
+ */
+ hasdefault = false;
+ typedefault = (Datum) 0;
+ typlen = sizeof(Oid);
+ typbyval = true;
+ }
+ else
+ {
+#ifdef _DROP_COLUMN_HACK__
+ if (COLUMN_IS_DROPPED(att_tup))
+ {
+ hasdefault = false;
+ typedefault = (Datum) 0;
+ }
+ else
+#endif /* _DROP_COLUMN_HACK__ */
+ hasdefault = get_typdefault(atttype, &typedefault);
+
+ get_typlenbyval(atttype, &typlen, &typbyval);
+ }
+
+ expr = (Node *) makeConst(atttype,
+ typlen,
+ typedefault,
+ !hasdefault,
+ typbyval,
+ false, /* not a set */
+ false);
+
+ /*
+ * If the column is a fixed-length type, it may need a length coercion
+ * as well as a type coercion. But NULLs don't need that.
+ */
+ if (hasdefault)
+ expr = coerce_type_typmod(NULL, expr,
+ atttype, atttypmod);
+
+ return expr;
+}
* Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $Header: /cvsroot/pgsql/src/backend/parser/analyze.c,v 1.206 2001/10/31 04:49:43 momjian Exp $
+ * $Header: /cvsroot/pgsql/src/backend/parser/analyze.c,v 1.207 2001/11/02 20:23:02 tgl Exp $
*
*-------------------------------------------------------------------------
*/
List *icolumns;
List *attrnos;
List *attnos;
- int numuseratts;
List *tl;
- TupleDesc rd_att;
qry->commandType = CMD_INSERT;
pstate->p_is_insert = true;
/*
* Prepare columns for assignment to target table.
*/
- numuseratts = 0;
attnos = attrnos;
foreach(tl, qry->targetList)
{
id = (Ident *) lfirst(icolumns);
updateTargetListEntry(pstate, tle, id->name, lfirsti(attnos),
id->indirection);
- numuseratts++;
icolumns = lnext(icolumns);
attnos = lnext(attnos);
}
/*
- * It is possible that the targetlist has fewer entries than were in
- * the columns list. We do not consider this an error (perhaps we
- * should, if the columns list was explictly given?). We must
- * truncate the attrnos list to only include the attrs actually
- * provided, else we will fail to apply defaults for them below.
+ * XXX It is possible that the targetlist has fewer entries than were in
+ * the columns list. We do not consider this an error. Perhaps we
+ * should, if the columns list was explicitly given?
*/
- if (icolumns != NIL)
- attrnos = ltruncate(numuseratts, attrnos);
-
- /*
- * Add targetlist items to assign DEFAULT values to any columns that
- * have defaults and were not assigned to by the user.
- *
- * XXX wouldn't it make more sense to do this further downstream, after
- * the rule rewriter? As is, altering a column default will not
- * change the behavior of INSERTs in already-defined rules.
- */
- rd_att = pstate->p_target_relation->rd_att;
- if (rd_att->constr && rd_att->constr->num_defval > 0)
- {
- Form_pg_attribute *att = rd_att->attrs;
- AttrDefault *defval = rd_att->constr->defval;
- int ndef = rd_att->constr->num_defval;
-
- while (--ndef >= 0)
- {
- AttrNumber attrno = defval[ndef].adnum;
- Form_pg_attribute thisatt = att[attrno - 1];
- TargetEntry *te;
-
- if (intMember((int) attrno, attrnos))
- continue; /* there was a user-specified value */
-
- /*
- * No user-supplied value, so add a targetentry with DEFAULT
- * expr and correct data for the target column.
- */
- te = makeTargetEntry(makeResdom(attrno,
- thisatt->atttypid,
- thisatt->atttypmod,
- pstrdup(NameStr(thisatt->attname)),
- false),
- stringToNode(defval[ndef].adbin));
- qry->targetList = lappend(qry->targetList, te);
-
- /*
- * Make sure the value is coerced to the target column type
- * (might not be right type if it's not a constant!)
- */
- updateTargetListEntry(pstate, te, te->resdom->resname, attrno,
- NIL);
- }
- }
/* done building the range table and jointree */
qry->rtable = pstate->p_rtable;
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