这个语句如何写
select visible,ydqx = case
when post_id =1 then 4
when post_id =2 then 4
when ui.Department_id=ar.Department_id then 3
---when user_id=10004 then 1
---when user_id <> 10004 then 2
else 2 end from userinfo ui , article ar--
where id=4114 and user_id=10004
and ydqx > =visible
ydqx 是表中没有的列,在 'and ydqx > =visible '中总是报:列名 'ydqx ' 无效。
不知道该如何在where 后引用 ydqx
[解决办法]
計算列不能直接拿來使用，必須寫全
select visible,ydqx = case
when post_id =1 then 4
when post_id =2 then 4
when ui.Department_id=ar.Department_id then 3
---when user_id=10004 then 1
---when user_id <> 10004 then 2
else 2 end from userinfo ui , article ar--
where id=4114 and user_id=10004
and (case
when post_id =1 then 4
when post_id =2 then 4
when ui.Department_id=ar.Department_id then 3
---when user_id=10004 then 1
---when user_id <> 10004 then 2
else 2 end) > =visible
