请教个GROUP BY的问题

[重典]

这是我的LINQ:

var ret = (from h in db.house_source_list
group h by h.account_id into g
where g.Count() < 30
select g.Key)
.Take(50);


生成的SQL（执行会出错）：

SELECT
`Limit1`.`account_id`
FROM (SELECT
`GroupBy1`.`K1` AS `account_id`
FROM (SELECT
COUNT(1) AS `A1`
FROM `house_source_list` AS `Extent1`
GROUP BY
`Extent1`.`account_id`) AS `GroupBy1`
WHERE `GroupBy1`.`A1` < 30 LIMIT 50) AS `Limit1`


出错原因是 内层的SELECT 只取出 COUNT(1), 而我最后的结果需要 GroupBy1`.`K1` AS `account_id` -- Group by 的KEY


请问LINQ需要怎么调整呢？谢谢

[重典]

我想生成的 SQL是

SELECT `Limit1`.`account_id`FROM
(SELECT `GroupBy1`.`K1` AS `account_id` FROM
(SELECT COUNT(1) AS `A1`, Extent1`.`account_id` as GroupBy1`.`K1` FROM `house_source_list` AS `Extent1`
GROUP BY `Extent1`.`account_id`) AS `GroupBy1`

WHERE `GroupBy1`.`A1` < 30 LIMIT 50) AS `Limit1`


标红色的地方，是没有生成出来的

[重典]

就是说 我无法让 group by 后的结果，查询出 key

[APOLLO_TS]

你那是什么数据库？

(from e in Employees
group e by e.City into z
where z.Count()<50
select z.Key).Take(50)

-- Region Parameters
DECLARE @p0 Int SET @p0 = 50
-- EndRegion
SELECT TOP (50) [t1].[City]
FROM (
SELECT COUNT(*) AS [value], [t0].[City]
FROM [Employees] AS [t0]
GROUP BY [t0].[City]
) AS [t1]
WHERE [t1].[value] < @p0

[重典]

MySql 的数据库..... 不会是因为MySql的数据库支持不好吧.....

[yingyuebingya]

SELECT COUNT(1) AS `A1`, Extent1`.`account_id` as GroupBy1`.`K1` 
FROM `house_source_list` AS `Extent1`
GROUP BY `Extent1`.`account_id
// GroupBy1 ...

[q107770540]

你这句翻译成SQL应该是什么样子的

[huminghua]

你放到SQLSERVER里面执行一下！试试！

[bourbon1795]

目前linq还不支持mysql.

[henory_lin]

建议用 linqPad 可以调试

[yucuihaimeng]

[Quote=引用 8 楼 bourbon1795 的回复:]
目前linq还不支持mysql.
[/Quote]
模糊中记得也是这样的 ，LINQ TO SQL 好像是只支持 SQL Server 数据库，但愿不要误导了你....

[Teng_s2000]

最好还是用MSSQL吧

默认的Provider只对SQL Server支持的好些

[q107770540]

var ret = (from h in db.house_source_list
group h by h.account_id into g
let c=g.Count()
where c < 30
select g.Key)
.Take(50);

[kingdom_0]

var ret = (from h in db.house_source_list
  group h by h.account_id into g
  let c=g.Count()
  where c < 30
  select g.Key)
  .Take(50);

[claymore1114]

MySql 数据库问题。

[ljyabc1028]

var mm = from t in context.Subject group t by t.StudentName into m select new Entity.Class1{ ID = m.Key, UserID = m.Count(), UserType =m.Sum(p => p.Grade) };
,这也是一个相似的例子

[kingdom_0]

[Quote=引用 10 楼 teng_s2000 的回复:]

最好还是用MSSQL吧

默认的Provider只对SQL Server支持的好些
[/Quote]恩恩.