有如下两张表:
A(ID, B_ID, Detail)
B(ID, Cnt)
B.Cnt为计数值,值为Select Count(*) As ACnt, B_ID From A Group By B_ID得到的ACnt求一段命令,能用来更新B.Cnt的值,谢谢。
A(ID, B_ID, Detail)
B(ID, Cnt)
B.Cnt为计数值,值为Select Count(*) As ACnt, B_ID From A Group By B_ID得到的ACnt求一段命令,能用来更新B.Cnt的值,谢谢。
(Select Count(*) As ACnt, B_ID From A Group By B_ID) tmp on B.ID=tmp.B_ID