**如果数据存在就删除数据库** ***** ~~~ DROP TABLE IF EXISTS `tablename`; ~~~ **二、判断数据库中的表是否存在** ***** ~~~ select * from information_schema.tables where table_name = 'f4E420295Aa194CAfFB2e75910CC87d4nTCw' AND TABLE_SCHEMA = '$mysql_data' ~~~