SQL 查询的时候加上一个条件

Question

orderid     billmode                                           currentOrderStatus 
----------- -------------------------------------------------- ------------------ 
390         货到付款                                               2
391         银行转账                                               6
392         货到付款                                               2
393         财付通                                                2
394         货到付款                                               2
395         上门自提                                               2select * from cv_order if(billmode<>'货到付款') then currentOrderStatus=3这个语句是错的，
我想实现的的结果是，查询所有的内容，但是如果billmode<>'货到付款'的话，要满足条件currentOrderStatus=3，哪位帮忙解决一下

Answer 1

select * from cv_order where currentOrderStatus=(case when billmode<>'货到付款' then 3 else '' end)

Answer 2

select * from cv_order
 WHERE currentOrderStatus= CASE WHEN billmode<>'货到付款' then 3 ELSE currentOrderStatus  END

Answer 3

select * 
from cv_order
where
currentOrderStatus=(case when billmode<>'货到付款' then 3 else currentOrderStatus end)

Answer 4

select * from cv_order where currentOrderStatus=(case when billmode<>'货到付款'
then 3 else currentOrderStatus End )

Answer 5

select * from cv_order
 WHERE ( billmode<>'货到付款' AND currentOrderStatus =3 )
 OR (billmode='货到付款' AND currentOrderStatus =currentOrderStatus )