DCL

**Table 1** DCL syntax compatibility
Description	Syntax	Difference
Set names with COLLATE specified.	SET [ SESSION \| LOCAL ] NAMES {'charset_name' [COLLATE 'collation_name'] \| DEFAULT};	GaussDB does not allow charset_name to be different from the database character set. For details, see "SQL Reference > SQL Syntax > SQL Statements > S > SET" in M Compatibility Developer Guide.
Switch the current mode with USE.	USE schema_name	If the USE statement is used to specify a schema and the user does not have USAGE permissions on the schema, MySQL reports an error while GaussDB specifies the current schema as null. -- MySQL mysql> USE test; ERROR 1044 (42000): Access denied for user 'u1'@'%' to database 'test' -- GaussDB m_db=> USE test; SET m_db=> SELECT database(); ERROR: function returned NULL CONTEXT: referenced column: database