1.SELECT servid FROM project,employee WHERE servid=empid and servid='a089' and grade=1;
2.SELECT * FROM project,employee WHERE servid=empid and servid='a089' and grade>1;楼主是这个意思吗?
2.SELECT * FROM project,employee WHERE servid=empid and servid='a089' and grade>1;楼主是这个意思吗?
当grade=1,就查出project中servid='089a'的值,
那么就可以分两种情况写用or,让条件为真select * from project where servid='089a' or (select grade from employee where empid='089a') > 1这句话我在MYSQL4.1测试成功
select ta.* from project ta,employee tb where servid='089a' or tb.grade > 1