零基础一站式安卓逆向

MySQL 对待 EXISTS 子句时，仍然采用嵌套子查询的执行方式。如下面的 SQL 语句：

SELECT *FROM my_neighbor nLEFT JOIN my_neighbor_apply sraON n.id = sra.neighbor_idAND sra.user_id = 'xxx'WHERE n.topic_status < 4AND EXISTS(SELECT 1FROM message_info mWHERE n.id = m.neighbor_id