mysql - Sql 案例与案例 Order by

Question

select id, username, email, 
 case
 when username = email then 'true'
 else 'false' 
 end 
 from users

有没有一种简单的方法可以当 username = email then 'true' as order_col 或 from users where case = true

问题是您能否将 case 包装在 AS case 中，然后对其进行排序或在该 case 上使用Where 语句。

Answer 1

 select id, username, email, 
             case when username = email 
                  then 'true'
                  else 'false' 
             end as usr_is_email
 from users
 order by usr_is_email