MYSQL案例陈述多个条件

Question

请帮助检查以下sql代码中的错误：

select
case when (z.mso_group_id = '3' and z.model_id = '22887081') then coalesce(level_2_id,996) level_2_id
      when (z.mso_group_id = '4' and z.model_id = '22911859') then coalesce(level_2_id,997) level_2_id
      when (z.mso_group_id = '5' and z.model_id = '22915074') then coalesce(level_2_id,998) level_2_id
      when (z.mso_group_id = '2' and z.model_id = '22908275') then coalesce(level_2_id,999) level_2_id
  end level_2_id
from
database_name

Answer 1

您正在重复列别名。你打算这个吗？

select (case when (z.mso_group_id = '3' and z.model_id = '22887081') then coalesce(level_2_id,996)
             when (z.mso_group_id = '4' and z.model_id = '22911859') then coalesce(level_2_id,997)
             when (z.mso_group_id = '5' and z.model_id = '22915074') then coalesce(level_2_id,998)
             when (z.mso_group_id = '2' and z.model_id = '22908275') then coalesce(level_2_id,999)
        end) as level_2_id
from database_name;