一个语句是：
insert into a (feiyong) values(zijin * feilv);
但是当zijin*feilv小于5时，按5插入，怎么办？
------解决方案--------------------
- SQL code
insert into a (feiyong) select case when zijin * feilv <5 then 5 else zijin * feilv end
------解决方案--------------------
- SQL code
insert into a (feiyong) select case when zijin * feilv < 5 then 5 else zijin * feilv end
------解决方案--------------------
- SQL code
insert into a (feiyong) values(case when zijin * feilv<5 then 5 else zijin * feilv end)