2012-02-28 99 views
0

我試圖在Visual Basic中學習EF。我正在努力尋找任何易於理解的簡單教程,如何做內部連接。實體框架VB加入

這是我想要的EF複製SQL:

SELECT Quote.LockedDateTime, IncommingQuoteStatus.StatusDesc, Users.FirstName 
+ ' ' + Users.LastName AS UserName 
FROM Quote 
INNER JOIN IncommingQuoteStatus ON IncommingQuoteStatus.StatusID = Quote.Status 
INNER JOIN Users ON Quote.LockedUserID = Users.UserID WHERE Quote.QuoteID = 1111; 

我知道有做EF的一個很短的手的方式,但我需要讓事情變得簡單和可讀性可能因爲我是垃圾!這是那種事情,我一直在努力:

Using db2 As New quotingSystemDevEntities 
    Dim User = (From Users In db.Users Where Users.UserID = Quote.LockedUserID _ 
     Select Users).SingleOrDefault 
    ' Now I can do something 
End Using 

如果有任何人能夠以明確的方式打下了這一點,這樣我可以從中吸取教訓,將是偉大的!

回答

1

我想你指的是join關鍵字:

From u In db.Users Join q In dq.Qoutes on u.UserID Equals q.LockedUserID 
Select New With { User = u, Quote = q } 

但在從數據庫User生成的數據上下文將有Quotes集合。所以你可以這樣做:

From u In db.Users.Include("Quotes") .... 

(方便,但轉化爲外部聯接)。