枕边姝的博客

SET SQL_SAFE_UPDATES=0;执行完这一句之后便可以增删改

select * from (select t1.id,t1.product_name_cd,t1.batch_num,t1.weight as w1,t2.weight as w2,IFNULL(t1.weight,0)-IFNULL(t2.weight,0) as diff from (select id,product_name_cd,batch_num, sum( weight