sqlserver 查询合并列

Question

sqlserver合并

Answer 1

你这个问题还有很大改进空间，但是看你的语句。我觉得说多了你不一定看得懂，你试试这个脚本吧，比较暴力，但是应该能出你要的结果SELECT  a.* ,
        b.a_count
FROM    ( SELECT  DISTINCT
                    COUNT(b.UserId) AS u_count ,
                    a.[TeachingClasses]
          FROM      [dbo].[Classes] a
                    LEFT JOIN [Classes_User] b ON a.[TeachingClasses] = b.[TeachingClasses]
          GROUP BY  a.[TeachingClasses]
        ) a
        INNER JOIN ( SELECT  DISTINCT
                            COUNT(c.UserId) AS a_count ,
                            a.[TeachingClasses]
                     FROM   [dbo].[Classes] a
                            LEFT JOIN [dbo].[Classes_ApproveUser] c ON a.[TeachingClasses] = c.[TeachingClasses]
                     GROUP BY a.[TeachingClasses]
                   ) b ON a.[TeachingClasses] = b.[TeachingClasses]

Answer 2

将两个多表查询的结果进行inner join，够暴力的，我喜欢。终于解决了！！！