关于group by inside inner join mysql答案

【问题标题】：Regarding group by inside inner join mysql关于group by inside inner join mysql
【发布时间】：2023-03-12 04:17:01
【问题描述】：

我正在通过 mysql 的内部连接尝试以下组。它说未知的列名。你能帮我解决这个问题吗？我在此查询“SELECT Min(Id) FROM testinbcalls group by lc.DBID”中收到错误，内部连接中说“groupby 中的未知列名 DBID”。如果 groupby 是，是否有另一种方法可以修改此查询不允许。我尝试了 ""SELECT Min(Id) FROM testinbcalls WHERE Id= lc.DBID" 而不是 group by，但它没有用。我不想将检查移到 where 子句，因为我希望在内部连接本身上过滤记录。谁能帮帮我。谢谢

SELECT DISTINCT ic.Id as `Id`,  lc.DBID,
init.Name as Init,
lc.TargetNumber as PhoneNumber, 
CONCAT(us.FirstName,' ',us.Surname) as UserName,
 iout.Name as Outc FROM 
 testcalls ic
 INNER JOIN testinit init on ic.InitId=init.Id
 INNER JOIN users us on ic.UserId=us.Id
 INNER JOIN testinbcalls lc ON ic.Id=lc.CallId AND  lc.DBID IS NOT NULL AND  ic.Id=(**SELECT Min(Id) FROM testinbcalls group by lc.DBID** )
 INNER JOIN (SELECT MIN(Id) Id FROM  testinbcalls  group by lc.DBID) mincallid ON ic.Id=mincallid.Id
 INNER JOIN icomes iout on ic.OutId=iout.Id 
 WHERE ic.AssignedDateTime between '2015-06-08 00:00:00' and '2015-06-09 23:59:59' ORDER BY Id DESC limit 250;

【问题讨论】：

标签： mysql

【解决方案1】：

您将其更改为下面删除表别名lc。这样，您实际上是在引用外部查询表。

INNER JOIN (SELECT MIN(Id) AS MinId FROM  testinbcalls  group by DBID)

【讨论】：

感谢信息。但我需要检查 ic.Id= MIN(Id) 来限制行
你可以像ic.Id=(SELECT Min(Id) FROM testinbcalls group by DBID )那样做