LINQ GROUP BY and MAX()
本文关键字:MAX and GROUP BY LINQ | 更新日期: 2023-09-27 18:30:29
我正在尝试找出如何在 LINQ 中编写 SQL 句子,但暂时找不到一种方法,这是 SQL 命令:
SELECT cs.Site_Name, MAX(ed.EffectiveDate_Date)
FROM [WAPMaster].[Factsheets].[EffectiveDate] ed,
[WAPMaster].[Configuration].[Site] cs
WHERE cs.Site_Id = ed.EffectiveDate_SiteId
GROUP BY cs.Site_Name
有人可以帮我使用 linq 语法吗?
**到目前为止我正在尝试这个(谢谢莱万列维)
var test = (from e in this._wapDatabase.EffectiveDates
join c in this._wapDatabase.Sites
on c.Site_Id equals e.EffectiveDate_SiteId
group e by c.Site_Name into r
select new
{
r.Key.SiteName,
EffectiveDate = r.Max(d => d.EffectiveDate_Date)
});
但是我收到以下错误:
https://i.stack.imgur.com/AkJ5V.png
SELECT cs.Site_Name ,
MAX(ed.EffectiveDate_Date)
FROM [WAPMaster].[Factsheets].[EffectiveDate] ed ,
[WAPMaster].[Configuration].[Site] cs
WHERE cs.Site_Id = ed.EffectiveDate_SiteId
GROUP BY cs.Site_Name
from e in WAPMaster.Factsheets.EffectiveDate
join c in WAPMaster.Configuration.Site
on c.Site_Id equals e.EffectiveDate_SiteId
group e by c.Site_Name into r
select new { SiteName = r.Key, EffectiveDate = r.Max(d=>d.EffectiveDate_Date)}
var test = (from effectiveDates in this._wapDatabase.EffectiveDates
from sites in this._wapDatabase.Sites
where sites.Site_Id = effectiveDates.EffectiveDate_SiteId
group effectiveDates by sites.Site_Id into g
select new { siteId = g.key , effectiveDate = g.max(ed => ed.EffectiveDate_Date)});