DROP objecttype IF EXISTS for the following objects:

table view index sequence schema type domain conversion

src/backend/commands/conversioncmds.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/conversioncmds.c,v 1.23 2005/10/15 02:49:15 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/conversioncmds.c,v 1.24 2005/11/19 17:39:44 adunstan Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -98,16 +98,29 @@ CreateConversionCommand(CreateConversionStmt *stmt)
  * DROP CONVERSION
  */
 void
-DropConversionCommand(List *name, DropBehavior behavior)
+DropConversionCommand(List *name, DropBehavior behavior, bool missing_ok)
 {
 	Oid			conversionOid;
 
 	conversionOid = FindConversionByName(name);
 	if (!OidIsValid(conversionOid))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("conversion \"%s\" does not exist",
-						NameListToString(name))));
+	{
+		if (! missing_ok)
+		{
+			ereport(ERROR,
+					(errcode(ERRCODE_UNDEFINED_OBJECT),
+					 errmsg("conversion \"%s\" does not exist",
+							NameListToString(name))));
+		}
+		else
+		{
+			ereport(NOTICE,
+					 (errmsg("conversion \"%s\" does not exist, skipping",
+							NameListToString(name))));
+		}
+
+		return;
+	}
 
 	ConversionDrop(conversionOid, behavior);
 }

src/backend/commands/schemacmds.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/schemacmds.c,v 1.35 2005/10/15 02:49:15 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/schemacmds.c,v 1.36 2005/11/19 17:39:44 adunstan Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -147,7 +147,7 @@ CreateSchemaCommand(CreateSchemaStmt *stmt)
  *		Removes a schema.
  */
 void
-RemoveSchema(List *names, DropBehavior behavior)
+RemoveSchema(List *names, DropBehavior behavior, bool missing_ok)
 {
 	char	   *namespaceName;
 	Oid			namespaceId;
@@ -163,9 +163,22 @@ RemoveSchema(List *names, DropBehavior behavior)
 								 CStringGetDatum(namespaceName),
 								 0, 0, 0);
 	if (!OidIsValid(namespaceId))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_SCHEMA),
-				 errmsg("schema \"%s\" does not exist", namespaceName)));
+	{
+		if (!missing_ok)
+		{
+			ereport(ERROR,
+					(errcode(ERRCODE_UNDEFINED_SCHEMA),
+					 errmsg("schema \"%s\" does not exist", namespaceName)));
+		}
+		else
+		{
+			ereport(NOTICE,
+					 (errmsg("schema \"%s\" does not exist, skipping", 
+							namespaceName)));
+		}
+
+		return;
+	}
 
 	/* Permission check */
 	if (!pg_namespace_ownercheck(namespaceId, GetUserId()))

src/backend/commands/typecmds.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/typecmds.c,v 1.82 2005/10/18 01:06:24 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/typecmds.c,v 1.83 2005/11/19 17:39:44 adunstan Exp $
  *
  * DESCRIPTION
  *	  The "DefineFoo" routines take the parse tree and pick out the
@@ -398,7 +398,7 @@ DefineType(List *names, List *parameters)
  *		Removes a datatype.
  */
 void
-RemoveType(List *names, DropBehavior behavior)
+RemoveType(List *names, DropBehavior behavior, bool missing_ok)
 {
 	TypeName   *typename;
 	Oid			typeoid;
@@ -414,10 +414,23 @@ RemoveType(List *names, DropBehavior behavior)
 	/* Use LookupTypeName here so that shell types can be removed. */
 	typeoid = LookupTypeName(typename);
 	if (!OidIsValid(typeoid))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("type \"%s\" does not exist",
-						TypeNameToString(typename))));
+	{
+		if (!missing_ok)
+		{
+			ereport(ERROR,
+					(errcode(ERRCODE_UNDEFINED_OBJECT),
+					 errmsg("type \"%s\" does not exist",
+							TypeNameToString(typename))));
+		}
+		else
+		{
+			ereport(NOTICE,
+					 (errmsg("type \"%s\" does not exist, skipping",
+							TypeNameToString(typename))));
+		}
+
+		return;
+	}
 
 	tup = SearchSysCache(TYPEOID,
 						 ObjectIdGetDatum(typeoid),
@@ -779,7 +792,7 @@ DefineDomain(CreateDomainStmt *stmt)
  * This is identical to RemoveType except we insist it be a domain.
  */
 void
-RemoveDomain(List *names, DropBehavior behavior)
+RemoveDomain(List *names, DropBehavior behavior, bool missing_ok)
 {
 	TypeName   *typename;
 	Oid			typeoid;
@@ -796,10 +809,23 @@ RemoveDomain(List *names, DropBehavior behavior)
 	/* Use LookupTypeName here so that shell types can be removed. */
 	typeoid = LookupTypeName(typename);
 	if (!OidIsValid(typeoid))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("type \"%s\" does not exist",
-						TypeNameToString(typename))));
+	{
+		if (!missing_ok)
+		{
+			ereport(ERROR,
+					(errcode(ERRCODE_UNDEFINED_OBJECT),
+					 errmsg("type \"%s\" does not exist",
+							TypeNameToString(typename))));
+		}
+		else
+		{
+			ereport(NOTICE,
+					 (errmsg("type \"%s\" does not exist, skipping",
+							TypeNameToString(typename))));
+		}
+
+		return;
+	}
 
 	tup = SearchSysCache(TYPEOID,
 						 ObjectIdGetDatum(typeoid),

src/backend/parser/gram.y

@@ -11,7 +11,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/parser/gram.y,v 2.512 2005/11/13 19:11:28 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/parser/gram.y,v 2.513 2005/11/19 17:39:44 adunstan Exp $
  *
  * HISTORY
  *	  AUTHOR			DATE			MAJOR EVENT
@@ -173,7 +173,7 @@ static void doNegateFloat(Value *v);
 %type <ival>	opt_lock lock_type cast_context
 %type <boolean>	opt_force opt_or_replace
 				opt_grant_grant_option opt_grant_admin_option
-				opt_nowait
+				opt_nowait 
 
 %type <boolean>	like_including_defaults
 
@@ -362,7 +362,7 @@ static void doNegateFloat(Value *v);
 
 	HANDLER HAVING HEADER HOLD HOUR_P
 
-	ILIKE IMMEDIATE IMMUTABLE IMPLICIT_P IN_P INCLUDING INCREMENT
+	IF_P ILIKE IMMEDIATE IMMUTABLE IMPLICIT_P IN_P INCLUDING INCREMENT
 	INDEX INHERIT INHERITS INITIALLY INNER_P INOUT INPUT_P
 	INSENSITIVE INSERT INSTEAD INT_P INTEGER INTERSECT
 	INTERVAL INTO INVOKER IS ISNULL ISOLATION
@@ -2818,20 +2818,32 @@ DropOpClassStmt:
  *
  *		QUERY:
  *
- *		DROP itemtype itemname [, itemname ...] [ RESTRICT | CASCADE ]
+ *		DROP itemtype [ IF EXISTS ] itemname [, itemname ...] 
+ *           [ RESTRICT | CASCADE ]
  *
  *****************************************************************************/
 
-DropStmt:	DROP drop_type any_name_list opt_drop_behavior
+DropStmt:	DROP drop_type IF_P EXISTS any_name_list opt_drop_behavior
 				{
 					DropStmt *n = makeNode(DropStmt);
 					n->removeType = $2;
+					n->missing_ok = TRUE;
+					n->objects = $5;
+					n->behavior = $6;
+					$$ = (Node *)n;
+				}
+			| DROP drop_type any_name_list opt_drop_behavior
+				{
+					DropStmt *n = makeNode(DropStmt);
+					n->removeType = $2;
+					n->missing_ok = FALSE;
 					n->objects = $3;
 					n->behavior = $4;
 					$$ = (Node *)n;
 				}
 		;
 
+
 drop_type:	TABLE									{ $$ = OBJECT_TABLE; }
 			| SEQUENCE								{ $$ = OBJECT_SEQUENCE; }
 			| VIEW									{ $$ = OBJECT_VIEW; }
@@ -8159,6 +8171,7 @@ unreserved_keyword:
 			| HEADER
 			| HOLD
 			| HOUR_P
+			| IF_P
 			| IMMEDIATE
 			| IMMUTABLE
 			| IMPLICIT_P

src/backend/parser/keywords.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/parser/keywords.c,v 1.166 2005/10/15 02:49:22 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/parser/keywords.c,v 1.167 2005/11/19 17:39:44 adunstan Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -160,6 +160,7 @@ static const ScanKeyword ScanKeywords[] = {
 	{"header", HEADER},
 	{"hold", HOLD},
 	{"hour", HOUR_P},
+	{"if",IF_P},
 	{"ilike", ILIKE},
 	{"immediate", IMMEDIATE},
 	{"immutable", IMMUTABLE},

src/backend/tcop/utility.c

@@ -10,7 +10,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/tcop/utility.c,v 1.245 2005/10/15 02:49:27 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/tcop/utility.c,v 1.246 2005/11/19 17:39:45 adunstan Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -67,6 +67,7 @@ struct msgstrings
 	char		kind;
 	int			nonexistent_code;
 	const char *nonexistent_msg;
+	const char *skipping_msg;
 	const char *nota_msg;
 	const char *drophint_msg;
 };
@@ -75,26 +76,31 @@ static const struct msgstrings msgstringarray[] = {
 	{RELKIND_RELATION,
 		ERRCODE_UNDEFINED_TABLE,
 		gettext_noop("table \"%s\" does not exist"),
+		gettext_noop("table \"%s\" does not exist, skipping"),
 		gettext_noop("\"%s\" is not a table"),
 	gettext_noop("Use DROP TABLE to remove a table.")},
 	{RELKIND_SEQUENCE,
 		ERRCODE_UNDEFINED_TABLE,
 		gettext_noop("sequence \"%s\" does not exist"),
+		gettext_noop("sequence \"%s\" does not exist, skipping"),
 		gettext_noop("\"%s\" is not a sequence"),
 	gettext_noop("Use DROP SEQUENCE to remove a sequence.")},
 	{RELKIND_VIEW,
 		ERRCODE_UNDEFINED_TABLE,
 		gettext_noop("view \"%s\" does not exist"),
+		gettext_noop("view \"%s\" does not exist, skipping"),
 		gettext_noop("\"%s\" is not a view"),
 	gettext_noop("Use DROP VIEW to remove a view.")},
 	{RELKIND_INDEX,
 		ERRCODE_UNDEFINED_OBJECT,
 		gettext_noop("index \"%s\" does not exist"),
+		gettext_noop("index \"%s\" does not exist, skipping"),
 		gettext_noop("\"%s\" is not an index"),
 	gettext_noop("Use DROP INDEX to remove an index.")},
 	{RELKIND_COMPOSITE_TYPE,
 		ERRCODE_UNDEFINED_OBJECT,
 		gettext_noop("type \"%s\" does not exist"),
+		gettext_noop("type \"%s\" does not exist, skipping"),
 		gettext_noop("\"%s\" is not a type"),
 	gettext_noop("Use DROP TYPE to remove a type.")},
 	{'\0', 0, NULL, NULL, NULL}
@@ -132,23 +138,40 @@ DropErrorMsgWrongType(char *relname, char wrongkind, char rightkind)
  * non-existent relation
  */
 static void
-DropErrorMsgNonExistent(RangeVar *rel, char rightkind)
+DropErrorMsgNonExistent(RangeVar *rel, char rightkind, bool missing_ok)
 {
 	const struct msgstrings *rentry;
 
 	for (rentry = msgstringarray; rentry->kind != '\0'; rentry++)
 	{
 		if (rentry->kind == rightkind)
-			ereport(ERROR,
-					(errcode(rentry->nonexistent_code),
-					 errmsg(rentry->nonexistent_msg, rel->relname)));
+		{
+			if (! missing_ok)
+			{
+				ereport(ERROR,
+						(errcode(rentry->nonexistent_code),
+						 errmsg(rentry->nonexistent_msg, rel->relname)));
+			}
+			else
+			{
+				ereport(NOTICE, (errmsg(rentry->skipping_msg, rel->relname)));
+				break;
+			}
+		}
 	}
 
-	Assert(false);				/* Should be impossible */
+	Assert(rentry->kind != '\0');	   /* Should be impossible */
 }
 
-static void
-CheckDropPermissions(RangeVar *rel, char rightkind)
+/*
+ * returns false if missing_ok is true and the object does not exist,
+ * true if object exists and permissions are OK,
+ * errors otherwise
+ *
+ */
+
+static bool
+CheckDropPermissions(RangeVar *rel, char rightkind, bool missing_ok)
 {
 	Oid			relOid;
 	HeapTuple	tuple;
@@ -156,7 +179,10 @@ CheckDropPermissions(RangeVar *rel, char rightkind)
 
 	relOid = RangeVarGetRelid(rel, true);
 	if (!OidIsValid(relOid))
-		DropErrorMsgNonExistent(rel, rightkind);
+	{
+		DropErrorMsgNonExistent(rel, rightkind, missing_ok);
+		return false;
+	}
 
 	tuple = SearchSysCache(RELOID,
 						   ObjectIdGetDatum(relOid),
@@ -183,6 +209,8 @@ CheckDropPermissions(RangeVar *rel, char rightkind)
 						rel->relname)));
 
 	ReleaseSysCache(tuple);
+
+	return true;
 }
 
 /*
@@ -528,31 +556,36 @@ ProcessUtility(Node *parsetree,
 					{
 						case OBJECT_TABLE:
 							rel = makeRangeVarFromNameList(names);
-							CheckDropPermissions(rel, RELKIND_RELATION);
-							RemoveRelation(rel, stmt->behavior);
+							if (CheckDropPermissions(rel, RELKIND_RELATION,
+													 stmt->missing_ok))
+								RemoveRelation(rel, stmt->behavior);
 							break;
 
 						case OBJECT_SEQUENCE:
 							rel = makeRangeVarFromNameList(names);
-							CheckDropPermissions(rel, RELKIND_SEQUENCE);
-							RemoveRelation(rel, stmt->behavior);
+							if (CheckDropPermissions(rel, RELKIND_SEQUENCE,
+													 stmt->missing_ok))
+								RemoveRelation(rel, stmt->behavior);
 							break;
 
 						case OBJECT_VIEW:
 							rel = makeRangeVarFromNameList(names);
-							CheckDropPermissions(rel, RELKIND_VIEW);
-							RemoveView(rel, stmt->behavior);
+							if (CheckDropPermissions(rel, RELKIND_VIEW,
+													 stmt->missing_ok))
+								RemoveView(rel, stmt->behavior);
 							break;
 
 						case OBJECT_INDEX:
 							rel = makeRangeVarFromNameList(names);
-							CheckDropPermissions(rel, RELKIND_INDEX);
-							RemoveIndex(rel, stmt->behavior);
+							if (CheckDropPermissions(rel, RELKIND_INDEX,
+													 stmt->missing_ok))
+								RemoveIndex(rel, stmt->behavior);
 							break;
 
 						case OBJECT_TYPE:
 							/* RemoveType does its own permissions checks */
-							RemoveType(names, stmt->behavior);
+							RemoveType(names, stmt->behavior, 
+									   stmt->missing_ok);
 							break;
 
 						case OBJECT_DOMAIN:
@@ -560,11 +593,13 @@ ProcessUtility(Node *parsetree,
 							/*
 							 * RemoveDomain does its own permissions checks
 							 */
-							RemoveDomain(names, stmt->behavior);
+							RemoveDomain(names, stmt->behavior, 
+										 stmt->missing_ok);
 							break;
 
 						case OBJECT_CONVERSION:
-							DropConversionCommand(names, stmt->behavior);
+							DropConversionCommand(names, stmt->behavior,
+												  stmt->missing_ok);
 							break;
 
 						case OBJECT_SCHEMA:
@@ -572,7 +607,8 @@ ProcessUtility(Node *parsetree,
 							/*
 							 * RemoveSchema does its own permissions checks
 							 */
-							RemoveSchema(names, stmt->behavior);
+							RemoveSchema(names, stmt->behavior,
+										 stmt->missing_ok);
 							break;
 
 						default: