一、一些常见的SQL实践(1)负向条件查询不能使用索引。select * from order where status!=0 and stauts!=1not in/not exists都不是好习惯。可以优化为in查询:select * from order where status in(2,3)(2)前导模糊查询不能使用索引。select * from order where desc...
新增字段 ALTER TABLE rcloud.rcloud_boss_config ADD is_show TINYINT (2) DEFAULT 1 COMMENT '是否展示 1展示 0不展示'; ALTER table rcloud.rcloud_boss_order ADD relevance_service text NOT NULL DEFAULT '' COMMENT ...
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MySQL 千万 级数据量根据(索引)优化 查询 速度https://www.cnblogs.com/phpdragon/p/8231533.html