SQl CASE WHEN 语句的嵌套使用方式

 select id,userid,  ys,
 
case
 
 when  pj_ys is NULL
 
 then ( case when  pj_ys1 is NUll then ys else pj_ys1 end) 
 
else pj_ys   end t
 
 from dbo.tbl_Emplyeeblogs

https://blog.csdn.net/spw55381155/article/details/79891192