utility.c

来自「PostgreSQL7.4.6 for Linux」· C语言 代码 · 共 1,566 行 · 第 1/3 页

 * where "dest" is passed on.
 */
bool
UtilityReturnsTuples(Node *parsetree)
{
	switch (nodeTag(parsetree))
	{
		case T_FetchStmt:
			{
				FetchStmt  *stmt = (FetchStmt *) parsetree;
				Portal		portal;

				if (stmt->ismove)
					return false;
				portal = GetPortalByName(stmt->portalname);
				if (!PortalIsValid(portal))
					return false;		/* not our business to raise error */
				return portal->tupDesc ? true : false;
			}

		case T_ExecuteStmt:
			{
				ExecuteStmt *stmt = (ExecuteStmt *) parsetree;
				PreparedStatement *entry;

				if (stmt->into)
					return false;
				entry = FetchPreparedStatement(stmt->name, false);
				if (!entry)
					return false;		/* not our business to raise error */
				switch (ChoosePortalStrategy(entry->query_list))
				{
					case PORTAL_ONE_SELECT:
						return true;
					case PORTAL_UTIL_SELECT:
						return true;
					case PORTAL_MULTI_QUERY:
						/* will not return tuples */
						break;
				}
				return false;
			}

		case T_ExplainStmt:
			return true;

		case T_VariableShowStmt:
			return true;

		default:
			return false;
	}
}

/*
 * UtilityTupleDescriptor
 *		Fetch the actual output tuple descriptor for a utility statement
 *		for which UtilityReturnsTuples() previously returned "true".
 *
 * The returned descriptor is created in (or copied into) the current memory
 * context.
 */
TupleDesc
UtilityTupleDescriptor(Node *parsetree)
{
	switch (nodeTag(parsetree))
	{
		case T_FetchStmt:
			{
				FetchStmt  *stmt = (FetchStmt *) parsetree;
				Portal		portal;

				if (stmt->ismove)
					return NULL;
				portal = GetPortalByName(stmt->portalname);
				if (!PortalIsValid(portal))
					return NULL;	/* not our business to raise error */
				return CreateTupleDescCopy(portal->tupDesc);
			}

		case T_ExecuteStmt:
			{
				ExecuteStmt *stmt = (ExecuteStmt *) parsetree;
				PreparedStatement *entry;

				if (stmt->into)
					return NULL;
				entry = FetchPreparedStatement(stmt->name, false);
				if (!entry)
					return NULL;	/* not our business to raise error */
				return FetchPreparedStatementResultDesc(entry);
			}

		case T_ExplainStmt:
			return ExplainResultDesc((ExplainStmt *) parsetree);

		case T_VariableShowStmt:
			{
				VariableShowStmt *n = (VariableShowStmt *) parsetree;

				return GetPGVariableResultDesc(n->name);
			}

		default:
			return NULL;
	}
}


/*
 * CreateCommandTag
 *		utility to get a string representation of the
 *		command operation, given a raw (un-analyzed) parsetree.
 *
 * This must handle all raw command types, but since the vast majority
 * of 'em are utility commands, it seems sensible to keep it here.
 *
 * NB: all result strings must be shorter than COMPLETION_TAG_BUFSIZE.
 * Also, the result must point at a true constant (permanent storage).
 */
const char *
CreateCommandTag(Node *parsetree)
{
	const char *tag;

	switch (nodeTag(parsetree))
	{
		case T_InsertStmt:
			tag = "INSERT";
			break;

		case T_DeleteStmt:
			tag = "DELETE";
			break;

		case T_UpdateStmt:
			tag = "UPDATE";
			break;

		case T_SelectStmt:
			tag = "SELECT";
			break;

		case T_TransactionStmt:
			{
				TransactionStmt *stmt = (TransactionStmt *) parsetree;

				switch (stmt->kind)
				{
					case TRANS_STMT_BEGIN:
						tag = "BEGIN";
						break;

					case TRANS_STMT_START:
						tag = "START TRANSACTION";
						break;

					case TRANS_STMT_COMMIT:
						tag = "COMMIT";
						break;

					case TRANS_STMT_ROLLBACK:
						tag = "ROLLBACK";
						break;

					default:
						tag = "???";
						break;
				}
			}
			break;

		case T_DeclareCursorStmt:
			tag = "DECLARE CURSOR";
			break;

		case T_ClosePortalStmt:
			tag = "CLOSE CURSOR";
			break;

		case T_FetchStmt:
			{
				FetchStmt  *stmt = (FetchStmt *) parsetree;

				tag = (stmt->ismove) ? "MOVE" : "FETCH";
			}
			break;

		case T_CreateDomainStmt:
			tag = "CREATE DOMAIN";
			break;

		case T_CreateSchemaStmt:
			tag = "CREATE SCHEMA";
			break;

		case T_CreateStmt:
			tag = "CREATE TABLE";
			break;

		case T_DropStmt:
			switch (((DropStmt *) parsetree)->removeType)
			{
				case OBJECT_TABLE:
					tag = "DROP TABLE";
					break;
				case OBJECT_SEQUENCE:
					tag = "DROP SEQUENCE";
					break;
				case OBJECT_VIEW:
					tag = "DROP VIEW";
					break;
				case OBJECT_INDEX:
					tag = "DROP INDEX";
					break;
				case OBJECT_TYPE:
					tag = "DROP TYPE";
					break;
				case OBJECT_DOMAIN:
					tag = "DROP DOMAIN";
					break;
				case OBJECT_CONVERSION:
					tag = "DROP CONVERSION";
					break;
				case OBJECT_SCHEMA:
					tag = "DROP SCHEMA";
					break;
				default:
					tag = "???";
			}
			break;

		case T_TruncateStmt:
			tag = "TRUNCATE TABLE";
			break;

		case T_CommentStmt:
			tag = "COMMENT";
			break;

		case T_CopyStmt:
			tag = "COPY";
			break;

		case T_RenameStmt:
			switch (((RenameStmt *) parsetree)->renameType)
			{
				case OBJECT_AGGREGATE:
					tag = "ALTER AGGREGATE";
					break;
				case OBJECT_CONVERSION:
					tag = "ALTER CONVERSION";
					break;
				case OBJECT_DATABASE:
					tag = "ALTER DATABASE";
					break;
				case OBJECT_FUNCTION:
					tag = "ALTER FUNCTION";
					break;
				case OBJECT_GROUP:
					tag = "ALTER GROUP";
					break;
				case OBJECT_LANGUAGE:
					tag = "ALTER LANGUAGE";
					break;
				case OBJECT_OPCLASS:
					tag = "ALTER OPERATOR CLASS";
					break;
				case OBJECT_SCHEMA:
					tag = "ALTER SCHEMA";
					break;
				case OBJECT_TRIGGER:
					tag = "ALTER TRIGGER";
					break;
				case OBJECT_USER:
					tag = "ALTER USER";
					break;
				default:
					tag = "ALTER TABLE";
			}
			break;

		case T_AlterTableStmt:
			tag = "ALTER TABLE";
			break;

		case T_AlterDomainStmt:
			tag = "ALTER DOMAIN";
			break;

		case T_GrantStmt:
			{
				GrantStmt  *stmt = (GrantStmt *) parsetree;

				tag = (stmt->is_grant) ? "GRANT" : "REVOKE";
			}
			break;

		case T_DefineStmt:
			switch (((DefineStmt *) parsetree)->kind)
			{
				case OBJECT_AGGREGATE:
					tag = "CREATE AGGREGATE";
					break;
				case OBJECT_OPERATOR:
					tag = "CREATE OPERATOR";
					break;
				case OBJECT_TYPE:
					tag = "CREATE TYPE";
					break;
				default:
					tag = "???";
			}
			break;

		case T_CompositeTypeStmt:
			tag = "CREATE TYPE";
			break;

		case T_ViewStmt:
			tag = "CREATE VIEW";
			break;

		case T_CreateFunctionStmt:
			tag = "CREATE FUNCTION";
			break;

		case T_IndexStmt:
			tag = "CREATE INDEX";
			break;

		case T_RuleStmt:
			tag = "CREATE RULE";
			break;

		case T_CreateSeqStmt:
			tag = "CREATE SEQUENCE";
			break;

		case T_AlterSeqStmt:
			tag = "ALTER SEQUENCE";
			break;

		case T_RemoveAggrStmt:
			tag = "DROP AGGREGATE";
			break;

		case T_RemoveFuncStmt:
			tag = "DROP FUNCTION";
			break;

		case T_RemoveOperStmt:
			tag = "DROP OPERATOR";
			break;

		case T_CreatedbStmt:
			tag = "CREATE DATABASE";
			break;

		case T_AlterDatabaseSetStmt:
			tag = "ALTER DATABASE";
			break;

		case T_DropdbStmt:
			tag = "DROP DATABASE";
			break;

		case T_NotifyStmt:
			tag = "NOTIFY";
			break;

		case T_ListenStmt:
			tag = "LISTEN";
			break;

		case T_UnlistenStmt:
			tag = "UNLISTEN";
			break;

		case T_LoadStmt:
			tag = "LOAD";
			break;

		case T_ClusterStmt:
			tag = "CLUSTER";
			break;

		case T_VacuumStmt:
			if (((VacuumStmt *) parsetree)->vacuum)
				tag = "VACUUM";
			else
				tag = "ANALYZE";
			break;

		case T_ExplainStmt:
			tag = "EXPLAIN";
			break;

		case T_VariableSetStmt:
			tag = "SET";
			break;

		case T_VariableShowStmt:
			tag = "SHOW";
			break;

		case T_VariableResetStmt:
			tag = "RESET";
			break;

		case T_CreateTrigStmt:
			tag = "CREATE TRIGGER";
			break;

		case T_DropPropertyStmt:
			switch (((DropPropertyStmt *) parsetree)->removeType)
			{
				case OBJECT_TRIGGER:
					tag = "DROP TRIGGER";
					break;
				case OBJECT_RULE:
					tag = "DROP RULE";
					break;
				default:
					tag = "???";
			}
			break;

		case T_CreatePLangStmt:
			tag = "CREATE LANGUAGE";
			break;

		case T_DropPLangStmt:
			tag = "DROP LANGUAGE";
			break;

		case T_CreateUserStmt:
			tag = "CREATE USER";
			break;

		case T_AlterUserStmt:
			tag = "ALTER USER";
			break;

		case T_AlterUserSetStmt:
			tag = "ALTER USER";
			break;

		case T_DropUserStmt:
			tag = "DROP USER";
			break;

		case T_LockStmt:
			tag = "LOCK TABLE";
			break;

		case T_ConstraintsSetStmt:
			tag = "SET CONSTRAINTS";
			break;

		case T_CreateGroupStmt:
			tag = "CREATE GROUP";
			break;

		case T_AlterGroupStmt:
			tag = "ALTER GROUP";
			break;

		case T_DropGroupStmt:
			tag = "DROP GROUP";
			break;

		case T_CheckPointStmt:
			tag = "CHECKPOINT";
			break;

		case T_ReindexStmt:
			tag = "REINDEX";
			break;

		case T_CreateConversionStmt:
			tag = "CREATE CONVERSION";
			break;

		case T_CreateCastStmt:
			tag = "CREATE CAST";
			break;

		case T_DropCastStmt:
			tag = "DROP CAST";
			break;

		case T_CreateOpClassStmt:
			tag = "CREATE OPERATOR CLASS";
			break;

		case T_RemoveOpClassStmt:
			tag = "DROP OPERATOR CLASS";
			break;

		case T_PrepareStmt:
			tag = "PREPARE";
			break;

		case T_ExecuteStmt:
			tag = "EXECUTE";
			break;

		case T_DeallocateStmt:
			tag = "DEALLOCATE";
			break;

		default:
			elog(WARNING, "unrecognized node type: %d",
				 (int) nodeTag(parsetree));
			tag = "???";
			break;
	}

	return tag;
}