MySQL 判断某个数据库是否存在 && 某张数据表是否存在

判断某个数据库是否存在

SELECT * FROM information_schema.SCHEMATA 
WHERE SCHEMA_NAME = 'dbname';

判断某个数据库中某张数据表是否存在

SELECT * FROM information_schema.TABLES
WHERE TABLE_SCHEMA = 'dbname'
AND TABLE_NAME = 'tbname';