很多情况用户量多的时候 东西会被超购,所以我们要有个判断条件跟添加的一起写,不然2个SQL分开写一点意义都没用必然超出!
mybatis 例子
- insert into enterprisecontrol
- (enterprise_id,control_id,time,status)
- SELECT #{enterprise_id},#{control_id},#{time},#{status}
- from DUAL
- where not exists(select enterprisecontrol.enterpriseControl_id from enterprisecontrol where enterprise_id = #{enterprise_id} and control_id = #{control_id} );
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