diff options
Diffstat (limited to 'src/backend/commands/view.c')
| -rw-r--r-- | src/backend/commands/view.c | 53 |
1 files changed, 45 insertions, 8 deletions
diff --git a/src/backend/commands/view.c b/src/backend/commands/view.c index 46cdf0aca0b..91420319a88 100644 --- a/src/backend/commands/view.c +++ b/src/backend/commands/view.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/commands/view.c,v 1.69 2002/09/02 02:13:01 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/commands/view.c,v 1.70 2002/09/02 20:04:40 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -29,6 +29,9 @@ #include "utils/lsyscache.h" +static void checkViewTupleDesc(TupleDesc newdesc, TupleDesc olddesc); + + /*--------------------------------------------------------------------- * DefineVirtualRelation * @@ -111,15 +114,9 @@ DefineVirtualRelation(const RangeVar *relation, List *tlist, bool replace) /* * Create a tuple descriptor to compare against the existing view, * and verify it matches. - * - * XXX the error message is a bit cheesy here: would be useful to - * give a more specific complaint about the difference in the - * descriptors. No time for it at the moment though. */ descriptor = BuildDescForRelation(attrList); - if (!equalTupleDescs(descriptor, rel->rd_att)) - elog(ERROR, "Cannot change column set of existing view %s", - RelationGetRelationName(rel)); + checkViewTupleDesc(descriptor, rel->rd_att); /* * Seems okay, so return the OID of the pre-existing view. @@ -149,6 +146,46 @@ DefineVirtualRelation(const RangeVar *relation, List *tlist, bool replace) } } +/* + * Verify that tupledesc associated with proposed new view definition + * matches tupledesc of old view. This is basically a cut-down version + * of equalTupleDescs(), with code added to generate specific complaints. + */ +static void +checkViewTupleDesc(TupleDesc newdesc, TupleDesc olddesc) +{ + int i; + + if (newdesc->natts != olddesc->natts) + elog(ERROR, "Cannot change number of columns in view"); + /* we can ignore tdhasoid */ + + for (i = 0; i < newdesc->natts; i++) + { + Form_pg_attribute newattr = newdesc->attrs[i]; + Form_pg_attribute oldattr = olddesc->attrs[i]; + + /* XXX not right, but we don't support DROP COL on view anyway */ + if (newattr->attisdropped != oldattr->attisdropped) + elog(ERROR, "Cannot change number of columns in view"); + + if (strcmp(NameStr(newattr->attname), NameStr(oldattr->attname)) != 0) + elog(ERROR, "Cannot change name of view column \"%s\"", + NameStr(oldattr->attname)); + /* XXX would it be safe to allow atttypmod to change? Not sure */ + if (newattr->atttypid != oldattr->atttypid || + newattr->atttypmod != oldattr->atttypmod) + elog(ERROR, "Cannot change datatype of view column \"%s\"", + NameStr(oldattr->attname)); + /* We can ignore the remaining attributes of an attribute... */ + } + /* + * We ignore the constraint fields. The new view desc can't have any + * constraints, and the only ones that could be on the old view are + * defaults, which we are happy to leave in place. + */ +} + static RuleStmt * FormViewRetrieveRule(const RangeVar *view, Query *viewParse, bool replace) { |