Doris: 4.1.2
DROP USER IF EXISTS 'test'@['dev.test'];
ERROR 1105 (HY000): errCode = 2, detailMessage =
extraneous input '[' expecting {'(', '{', '}', 'ACTIONS', 'AFTER', 'AGG_STATE', 'AGGREGATE', 'ALIAS', 'ANALYZED', 'ARRAY', 'AT', 'AUTHORS', 'AUTHENTICATION', 'AUTO_INCREMENT', 'ALWAYS', 'BACKENDS', 'BACKUP', 'BEGIN', 'BELONG', 'BIN', 'BITAND', 'BITMAP', 'BITMAP_EMPTY', 'BITMAP_UNION', 'BITOR', 'BITXOR', 'BLOB', 'BOOLEAN', 'BRANCH', 'BRIEF', 'BROKER', 'BUCKETS', 'BUILD', 'BUILTIN', 'BULK', 'CACHE', 'CACHED', 'CALL', 'CANCEL', 'CASE', 'CAST', 'CATALOG', 'CATALOGS', 'CEL', 'CHAIN
去掉[]没用, 执行成功, 但是没删除用户
