*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/commands/Attic/command.c,v 1.63 2000/01/16 20:04:55 petere Exp $
+ * $Header: /cvsroot/pgsql/src/backend/commands/Attic/command.c,v 1.64 2000/01/22 14:20:45 petere Exp $
*
* NOTES
* The PortalExecutorHeapMemory crap needs to be eliminated
#include "catalog/pg_attrdef.h"
#include "catalog/pg_type.h"
#include "commands/command.h"
+#include "commands/rename.h"
#include "executor/execdefs.h"
#include "executor/executor.h"
#include "catalog/heap.h"
Relation idescs[Num_pg_attr_indices];
Relation ridescs[Num_pg_class_indices];
bool hasindex;
- List *rawDefaults = NIL;
+// List *rawDefaults = NIL;
/*
* permissions checking. this would normally be done in utility.c,
* Grab an exclusive lock on the target table, which we will NOT release
* until end of transaction.
*/
- rel = heap_openr((char *)relationName, AccessExclusiveLock);
+ rel = heap_openr(relationName, AccessExclusiveLock);
myrelid = RelationGetRelid(rel);
heap_close(rel, NoLock); /* close rel but keep lock! */
elog(ERROR, "ALTER TABLE: permission denied");
#endif
- /* XXX should heap_openr take const char * ? */
- rel = heap_openr((char *)relationName, AccessExclusiveLock);
+ rel = heap_openr(relationName, AccessExclusiveLock);
myrelid = RelationGetRelid(rel);
heap_close(rel, NoLock);
/* keep the system catalog indices current */
CatalogOpenIndices(Num_pg_attr_indices, Name_pg_attr_indices, irelations);
CatalogIndexInsert(irelations, Num_pg_attr_indices, attr_rel, newtuple);
- CatalogCloseIndices(Num_pg_class_indices, irelations);
+ CatalogCloseIndices(Num_pg_attrdef_indices, irelations);
/* get rid of actual default definition */
drop_default(myrelid, attnum);
/*
* ALTER TABLE DROP COLUMN
+ *
+ * Strategy:
+ * - permission/sanity checks
+ * - create a new table _ATDC<name> with all attributes minus the desired one
+ * - copy over all the data
+ * - make the column defaults point to the new table
+ * - kill the old table
+ * - rename the intermediate table back
*/
void
AlterTableDropColumn(const char *relationName,
bool inh, const char *colName,
int behavior)
{
- elog(NOTICE, "ALTER TABLE / DROP COLUMN is not implemented");
+ Relation oldrel, newrel, defrel;
+ HeapTuple tuple;
+ TupleDesc olddesc, newdesc, defdsc;
+ int16 dropattnum, oldnumatts;
+ Oid oldrel_oid, newrel_oid;
+ char tmpname[NAMEDATALEN];
+ int16 i;
+ HeapScanDesc scan;
+ ScanKeyData scankey;
+
+ if (!allowSystemTableMods && IsSystemRelationName(relationName))
+ elog(ERROR, "ALTER TABLE: relation \"%s\" is a system catalog",
+ relationName);
+#ifndef NO_SECURITY
+ if (!pg_ownercheck(UserName, relationName, RELNAME))
+ elog(ERROR, "ALTER TABLE: permission denied");
+#endif
+
+ oldrel = heap_openr(relationName, AccessExclusiveLock);
+ if (oldrel->rd_rel->relkind != RELKIND_RELATION)
+ {
+ heap_close(oldrel, AccessExclusiveLock);
+ elog(ERROR, "ALTER TABLE: relation %s is not a table", relationName);
+ }
+
+ oldrel_oid = ObjectIdGetDatum(RelationGetRelid(oldrel));
+ oldnumatts = RelationGetNumberOfAttributes(oldrel);
+
+ if (oldnumatts==1)
+ {
+ heap_close(oldrel, AccessExclusiveLock);
+ elog(ERROR, "ALTER TABLE: relation %s only has one column", relationName);
+ }
+
+/* What to do here? */
+/*
+ if (length(find_all_inheritors(RelationGetRelid(oldrel)))>0)
+ elog(ERROR, "ALTER TABLE: cannot drop a column on table that is inherited from");
+*/
+ /*
+ * get the number of the attribute
+ */
+ tuple = SearchSysCacheTuple(ATTNAME, oldrel_oid, NameGetDatum(namein(colName)), 0, 0);
+ if (!HeapTupleIsValid(tuple))
+ {
+ heap_close(oldrel, AccessExclusiveLock);
+ elog(ERROR, "ALTER TABLE: relation \"%s\" has no column \"%s\"",
+ relationName, colName);
+ }
+
+ dropattnum = ((Form_pg_attribute) GETSTRUCT(tuple))->attnum;
+
+ if (snprintf(tmpname, NAMEDATALEN, "_ATDC%s", relationName)==-1)
+ {
+ heap_close(oldrel, AccessExclusiveLock);
+ elog(ERROR, "AlterTableDropColumn: relation name too long");
+ }
+
+ /*
+ * Build descriptor for new relation
+ */
+ olddesc = RelationGetDescr(oldrel);
+
+ newdesc = CreateTemplateTupleDesc(oldnumatts-1);
+ for(i = 1; i < dropattnum; i++)
+ {
+ Form_pg_attribute att = olddesc->attrs[i-1];
+ TupleDescInitEntry(newdesc, i, nameout(&(att->attname)),
+ att->atttypid, att->atttypmod,
+ att->attnelems, att->attisset);
+ /* the above function doesn't take care of these two */
+ newdesc->attrs[i-1]->attnotnull = att->attnotnull;
+ newdesc->attrs[i-1]->atthasdef = att->atthasdef;
+ }
+
+ for(i = dropattnum; i <= oldnumatts-1; i++)
+ {
+ Form_pg_attribute att = olddesc->attrs[i];
+ TupleDescInitEntry(newdesc, i, nameout(&(att->attname)),
+ att->atttypid, att->atttypmod,
+ att->attnelems, att->attisset);
+ /* the above function doesn't take care of these two */
+ newdesc->attrs[i-1]->attnotnull = att->attnotnull;
+ newdesc->attrs[i-1]->atthasdef = att->atthasdef;
+ }
+
+ /* Create the new table */
+ newrel_oid = heap_create_with_catalog(tmpname, newdesc, RELKIND_RELATION, false);
+ if (newrel_oid == InvalidOid)
+ {
+ heap_close(oldrel, AccessExclusiveLock);
+ elog(ERROR, "ALTER TABLE: something went wrong");
+ }
+
+ /* Make the new table visible */
+ CommandCounterIncrement();
+
+ /*
+ * Copy over the data
+ */
+ newrel = heap_open(newrel_oid, AccessExclusiveLock);
+
+ scan = heap_beginscan(oldrel, false, SnapshotNow, 0, NULL);
+ while (HeapTupleIsValid(tuple = heap_getnext(scan, 0)))
+ {
+ bool isnull;
+ Datum *new_record;
+ bool *new_record_nulls;
+ HeapTuple new_tuple;
+
+ new_record = palloc((oldnumatts-1) * sizeof(*new_record));
+ new_record_nulls = palloc((oldnumatts-1) * sizeof(*new_record_nulls));
+
+ for(i = 1; i < dropattnum; i++)
+ {
+ new_record[i-1] = heap_getattr(tuple, i, olddesc, &isnull);
+ new_record_nulls[i-1] = isnull ? 'n' : ' ';
+ }
+ for(i = dropattnum+1; i <= oldnumatts; i++)
+ {
+ new_record[i-2] = heap_getattr(tuple, i, olddesc, &isnull);
+ new_record_nulls[i-2] = isnull ? 'n' : ' ';
+ }
+
+ new_tuple = heap_formtuple(newdesc, new_record, new_record_nulls);
+ Assert(new_tuple);
+
+ if (heap_insert(newrel, new_tuple) == InvalidOid)
+ elog(ERROR, "AlterTableDropColumn: heap_insert failed");
+
+ pfree(new_record);
+ pfree(new_record_nulls);
+ }
+ heap_endscan(scan);
+
+ heap_close(newrel, NoLock);
+ heap_close(oldrel, NoLock);
+
+ /*
+ * Move defaults over to the new table
+ */
+ defrel = heap_openr(AttrDefaultRelationName, AccessExclusiveLock);
+ defdsc = RelationGetDescr(defrel);
+
+ /* look for all entries referencing the old table */
+ ScanKeyEntryInitialize(&scankey, 0x0, Anum_pg_attrdef_adrelid, F_OIDEQ,
+ ObjectIdGetDatum(oldrel_oid));
+ scan = heap_beginscan(defrel, false, SnapshotNow, 1, &scankey);
+ while(HeapTupleIsValid(tuple = heap_getnext(scan, false)))
+ {
+ HeapTuple newtuple;
+ int2 attrnum;
+ Relation irelations[Num_pg_attrdef_indices];
+
+ attrnum = ((Form_pg_attrdef) GETSTRUCT(tuple))->adnum;
+
+ /* remove the entry about the dropped column */
+ if (attrnum == dropattnum)
+ {
+ heap_delete(defrel, &tuple->t_self, NULL);
+ continue;
+ }
+
+ newtuple = heap_copytuple(tuple);
+
+ if (attrnum > dropattnum)
+ ((Form_pg_attrdef) GETSTRUCT(newtuple))->adnum--;
+
+ /* make it point to the new table */
+ ((Form_pg_attrdef) GETSTRUCT(newtuple))->adrelid = newrel_oid;
+ heap_update(defrel, &tuple->t_self, newtuple, NULL);
+
+ /* keep the system catalog indices current */
+ CatalogOpenIndices(Num_pg_attrdef_indices, Name_pg_attrdef_indices, irelations);
+ CatalogIndexInsert(irelations, Num_pg_attrdef_indices, defrel, newtuple);
+ CatalogCloseIndices(Num_pg_attrdef_indices, irelations);
+ }
+ heap_endscan(scan);
+ heap_close(defrel, NoLock);
+
+ CommandCounterIncrement();
+
+ /* make the old table disappear */
+ heap_drop_with_catalog(relationName);
+ CommandCounterIncrement();
+
+ /* set back original name */
+ TypeRename(tmpname, relationName);
+ renamerel(tmpname, relationName);
}
+/*
+ * ALTER TABLE ADD CONSTRAINT
+ */
void
AlterTableAddConstraint(const char *relationName,
bool inh, Node *newConstraint)
{
- elog(NOTICE, "ALTER TABLE / ADD CONSTRAINT is not implemented");
+ elog(ERROR, "ALTER TABLE / ADD CONSTRAINT is not implemented");
}
-void AlterTableDropConstraint(const char *relationName,
- bool inh, const char *constrName,
- int behavior)
+/*
+ * ALTER TABLE DROP CONSTRAINT
+ */
+void
+AlterTableDropConstraint(const char *relationName,
+ bool inh, const char *constrName,
+ int behavior)
{
- elog(NOTICE, "ALTER TABLE / DROP CONSTRAINT is not implemented");
+ elog(ERROR, "ALTER TABLE / DROP CONSTRAINT is not implemented");
}
projects / postgresql / blobdiff