Linq Group by和內部加入

Question

我想替換此SQL命令：

string dotazBankUcty = @"SELECT 
     H.UCET, 
     SUM(H.KON_STAV_MD) AS KON_STAV_MD, 
     SUM(H.KON_STAV_DAL) AS KON_STAV_DAL , 
     SUM(H.KON_STAV_MD_MENA) AS KON_STAV_MD_MENA, 
     SUM(H.KON_STAV_DAL_MENA) AS KON_STAV_DAL_MENA, 
     MAX(UBUC.KOD_MENY) AS KOD_MENY 
     FROM UHLAVAKT H 
     inner join UBUC on H.UCET = UBUC.UCET GROUP BY H.UCET";

使用LINQ命令。 我試過了，但是它返回的是我想要的左聯接而不是內聯接。

var uhlavAktQuery = new XPQuery<UHLAVAKT>(CoreHelper.DataSession);

var ubucQuery = new XPQuery<UBUC>(CoreHelper.DataSession);

var resultBankyUcty = (from h in uhlavAktQuery
    join u in ubucQuery on h.CompoundKey1.UCET equals u.UCET
    group new { h, u } by new { h.CompoundKey1.UCET } into gUcty
                    select new
                    {
                    Ucet = gUcty.Key.UCET,
                    KON_STAV_MD = gUcty.Sum(k => k.h.KONSTAVMD),
                    KON_STAV_DAL = gUcty.Sum(k => k.h.KONSTAVDAL),
                    KON_STAV_MD_MENA = gUcty.Sum(k => k.h.KONSTAVMDMENA),
                    KON_STAV_DAL_MENA = gUcty.Sum(k => k.h.KONSTAVDALMENA),
                    KOD_MENY = gUcty.Max(k => k.u.KODMENY)
                    });

你能幫我嗎？

Answer 1

當我努力爭取加入LINQ的機會時，我發現以下有關CodeProject的文章非常有用，也很有幫助：

LINQ擴展聯接

在包括圖表的示例的幫助下，他解釋了聯接是什么，並介紹了實現各種聯接查詢的IEnumerable通用擴展方法。