Entity Frameworkクエリでの複数の結合

Question

長い時間のlurker、初めてのポスター。私は過去にここにいくつかの良い答えを見つけたので、私はここに来て、私は少し助けを得ることができるかどうかを見てください！

私は、LINQのにかなり新しいですし、私は私のオブジェクトのためのEntity Frameworkのを使用しています。私のプロジェクトには.edmxファイルがあります。すべての

まず私はVS 2010に付属のサンプル・ページから使用してSystem.Linq.Dynamicクラスをインポートしたので、私は私のページにこれを追加することができます。

System.Linq.Dynamicを使用して、

問題は、私の参加がうまくいっているとは思わないということです。

これは私の現在のコードです：

private void FetchData() 
{ 
    using (var Context = new ProjectEntities()) 
    { 
     var Query = 
      Context.Users 
      .Join(Context.UserStats,   // Table to Join 
       u => u.msExchMailboxGuid,  // Column to Join From 
       us => us.MailboxGuid,   // Column to Join To 
       (u, us) => new     // Alias names from Tables 
       { 
        u, 
        us 
       }) 
      .Join(Context.TechContacts,   // Table to Join 
       u => u.u.UserPrincipalName,  // Column to Join From 
       tc => tc.UPN,     // Column to Join To 
       (u, tc) => new     // Alias names from Tables 
       { 
        u = u, 
        tc = tc 
       }) 
       .Where(u => true) 
       .OrderBy("u.u.CompanyName") 
       .Select("New(u.u.CompanyName,tc.UPN,u.us.TotalItemSize)"); 

     // Add Extra Filters 
     if (!(string.IsNullOrWhiteSpace(SearchCompanyNameTextBox.Text))) 
     { 

      Query = Query.Where("u.CompanyName.Contains(@0)", SearchCompanyNameTextBox.Text); 
     } 

     // Set the Record Count 
     GlobalVars.TotalRecords = Query.Count(); 

     // Add Paging 
     Query = Query 
      .Skip(GlobalVars.Skip) 
      .Take(GlobalVars.Take); 

     // GridView Datasource Binding 
     GridViewMailboxes.DataSource = Query; 
     GridViewMailboxes.DataBind(); 
    } 
} 

これは、通常のSQLの場合と同様に、それは動作しますので、私はそれを書くことができますどのように？私は、動的.Where句と.Selectフィールド名を維持する必要があり

SELECT u.Column1, 
u.Column2, 
us.Column1, 
tc.Column1 
FROM Users AS u 
INNER JOIN UserStats AS us 
ON u.msExchMailboxGuid = us.MailboxGuid 
INNER JOIN TechContacts AS tc 
ON u.UserPrincipalName = tc.UPN 

、あなたが今見ることができるような問題は、私はそれが私の中にありますようu.CompanyNameフィールドを取り戻すためにuuCompanyNameを行う必要があるということです二度結合する。

私は今、しばらくの間、このためにGoogleで検索しないが、まだサイコロてきました。

ご迷惑をおかけして申し訳ありません。

EDIT - これは私の現在のクエリです。それは動作しますが、それは見て悪夢のビットです。

私に同行してください。たとえそれが少しでもあっても、私はここにすべてを含めたいと思っていました。

動的な列の選択は私にとって必須です。それ以外の場合は、テーブルアダプターとストアドプロシージャーを使用することもできます。より少ないデータを返すようにクエリを減らすことができれば、これが私の目標の1つです。誰かが改善を提案できるなら私はすべての耳ですか？

私は単に私のSELECT文の途中で私がしたい列を返す必要が参加したときに、私はSQLで、サブ項目に参加する選択することを停止する方法を見つけることができませんでした。

private void FetchData() 
{ 
    using (var Context = new ProjectEntities()) 
    { 
     string Fields = GetDynamicFields(); 

     var Query = 
      Context.Users 
      .Join(Context.UserStats,   // Table to Join 
       u => u.msExchMailboxGuid,  // Column to Join From 
       us => us.MailboxGuid,   // Column to Join To 
       (u, us) => new     // Declare Columns for the next Join 
       { 
        ObjectGuid = u.objectGuid, 
        msExchMailboxGuid = u.msExchMailboxGuid, 
        CompanyName = u.CompanyName, 
        ResellerOU = u.ResellerOU, 
        DisplayName = u.DisplayName, 
        MBXServer = u.MBXServer, 
        MBXSG = u.MBXSG, 
        MBXDB = u.MBXDB, 
        MBXWarningLimit = u.MBXWarningLimit, 
        MBXSendLimit = u.MBXSendLimit, 
        MBXSendReceiveLimit = u.MBXSendReceiveLimit, 
        extensionAttribute10 = u.extensionAttribute10, 
        legacyExchangeDN = u.legacyExchangeDN, 
        UserPrincipalName = u.UserPrincipalName, 
        Mail = u.Mail, 
        lastLogonTimeStamp = u.lastLogonTimestamp, 
        createTimeStamp = u.createTimeStamp, 
        modifyTimeStamp = u.modifyTimeStamp, 
        altRecipient = u.altRecipient, 
        altRecipientBL = u.altRecipientBL, 
        DeletedDate = u.DeletedDate, 
        MailboxGuid = us.MailboxGuid, 
        Date = us.Date, 
        AssociatedItemCount = us.AssociatedItemCount, 
        DeletedItemCount = us.DeletedItemCount, 
        ItemCount = us.ItemCount, 
        LastLoggedOnUserAccount = us.LastLoggedOnUserAccount, 
        LastLogonTime = us.LastLogonTime, 
        StorageLimitStatus = us.StorageLimitStatus, 
        TotalDeletedItemSize = us.TotalDeletedItemSize, 
        TotalItemSize = us.TotalItemSize, 
        MailboxDatabase = us.MailboxDatabase 
       }) 
      .Join(Context.TechContacts,   // Table to Join 
       u => u.UserPrincipalName,  // Column to Join From 
       tc => tc.UPN,     // Column to Join To 
       (u, tc) => new     // Declare Final Column Names 
       { 
        ObjectGuid = u.ObjectGuid, 
        msExchMailboxGuid = u.msExchMailboxGuid, 
        CompanyName = u.CompanyName, 
        ResellerOU = u.ResellerOU, 
        DisplayName = u.DisplayName, 
        MBXServer = u.MBXServer, 
        MBXSG = u.MBXSG, 
        MBXDB = u.MBXDB, 
        MBXWarningLimit = u.MBXWarningLimit, 
        MBXSendLimit = u.MBXSendLimit, 
        MBXSendReceiveLimit = u.MBXSendReceiveLimit, 
        extensionAttribute10 = u.extensionAttribute10, 
        legacyExchangeDN = u.legacyExchangeDN, 
        UserPrincipalName = u.UserPrincipalName, 
        Mail = u.Mail, 
        lastLogonTimeStamp = u.lastLogonTimeStamp, 
        createTimeStamp = u.createTimeStamp, 
        modifyTimeStamp = u.modifyTimeStamp, 
        altRecipient = u.altRecipient, 
        altRecipientBL = u.altRecipientBL, 
        DeletedDate = u.DeletedDate, 
        MailboxGuid = u.MailboxGuid, 
        Date = u.Date, 
        AssociatedItemCount = u.AssociatedItemCount, 
        DeletedItemCount = u.DeletedItemCount, 
        ItemCount = u.ItemCount, 
        LastLoggedOnUserAccount = u.LastLoggedOnUserAccount, 
        LastLogonTime = u.LastLogonTime, 
        StorageLimitStatus = u.StorageLimitStatus, 
        TotalDeletedItemSize = u.TotalDeletedItemSize, 
        TotalItemSize = u.TotalItemSize, 
        MailboxDatabase = u.MailboxDatabase, 
        // New Columns from this join 
        UPN = tc.UPN, 
        Customer_TechContact = tc.Customer_TechContact, 
        Customer_TechContactEmail = tc.Customer_TechContactEmail, 
        Reseller_TechContact = tc.Reseller_TechContact, 
        Reseller_TechContactEmail = tc.Reseller_TechContact, 
        Reseller_Name = tc.Reseller_Name 
       }) 
      .Where(u => true) 
      .OrderBy(GlobalVars.SortColumn + " " + GlobalVars.SortDirection) 
      .Select("New(" + Fields + ")"); 

     // Add Extra Filters 
     if (!(string.IsNullOrWhiteSpace(SearchCompanyNameTextBox.Text))) 
     { 
      Query = Query.Where("CompanyName.StartsWith(@0)", SearchCompanyNameTextBox.Text); 
     } 

     // Set the Record Count 
     GlobalVars.TotalRecords = Query.Count(); 

     // Add Paging 
     Query = Query 
      .Skip(GlobalVars.Skip) 
      .Take(GlobalVars.Take); 

     // GridView Datasource Binding 
     GridViewMailboxes.DataSource = Query; 
     GridViewMailboxes.DataBind(); 
    } 
} 

これは、SQLはバックグラウンドで実行するものである：

SELECT TOP (20) 
[Project1].[C1] AS [C1], 
[Project1].[objectGuid] AS [objectGuid], 
[Project1].[msExchMailboxGuid] AS [msExchMailboxGuid], 
[Project1].[CompanyName] AS [CompanyName], 
[Project1].[ResellerOU] AS [ResellerOU], 
[Project1].[DisplayName] AS [DisplayName], 
[Project1].[MBXServer] AS [MBXServer], 
[Project1].[MBXSG] AS [MBXSG], 
[Project1].[MBXDB] AS [MBXDB], 
[Project1].[MBXWarningLimit] AS [MBXWarningLimit], 
[Project1].[MBXSendLimit] AS [MBXSendLimit], 
[Project1].[MBXSendReceiveLimit] AS [MBXSendReceiveLimit], 
[Project1].[extensionAttribute10] AS [extensionAttribute10], 
[Project1].[legacyExchangeDN] AS [legacyExchangeDN], 
[Project1].[UserPrincipalName] AS [UserPrincipalName], 
[Project1].[Mail] AS [Mail], 
[Project1].[lastLogonTimestamp] AS [lastLogonTimestamp], 
[Project1].[createTimeStamp] AS [createTimeStamp], 
[Project1].[modifyTimeStamp] AS [modifyTimeStamp], 
[Project1].[altRecipient] AS [altRecipient], 
[Project1].[altRecipientBL] AS [altRecipientBL], 
[Project1].[DeletedDate] AS [DeletedDate] 
    FROM (SELECT [Project1].[objectGuid] AS [objectGuid], 
     [Project1].[msExchMailboxGuid] AS [msExchMailboxGuid], 
     [Project1].[CompanyName] AS [CompanyName], 
     [Project1].[ResellerOU] AS [ResellerOU], 
     [Project1].[DisplayName] AS [DisplayName], 
     [Project1].[MBXServer] AS [MBXServer], 
     [Project1].[MBXSG] AS [MBXSG], 
     [Project1].[MBXDB] AS [MBXDB], 
     [Project1].[MBXWarningLimit] AS [MBXWarningLimit], 
     [Project1].[MBXSendLimit] AS [MBXSendLimit], 
     [Project1].[MBXSendReceiveLimit] AS [MBXSendReceiveLimit], 
     [Project1].[extensionAttribute10] AS [extensionAttribute10], 
     [Project1].[legacyExchangeDN] AS [legacyExchangeDN], 
     [Project1].[UserPrincipalName] AS [UserPrincipalName], 
     [Project1].[Mail] AS [Mail], 
     [Project1].[lastLogonTimestamp] AS [lastLogonTimestamp], 
     [Project1].[createTimeStamp] AS [createTimeStamp], 
     [Project1].[modifyTimeStamp] AS [modifyTimeStamp], 
     [Project1].[altRecipient] AS [altRecipient], 
     [Project1].[altRecipientBL] AS [altRecipientBL], 
     [Project1].[DeletedDate] AS [DeletedDate], 
     [Project1].[C1] AS [C1], 
     row_number() OVER (ORDER BY [Project1].[CompanyName] ASC) AS [row_number] 
      FROM (SELECT 
       [Extent1].[objectGuid] AS [objectGuid], 
       [Extent1].[msExchMailboxGuid] AS [msExchMailboxGuid], 
       [Extent1].[CompanyName] AS [CompanyName], 
       [Extent1].[ResellerOU] AS [ResellerOU], 
       [Extent1].[DisplayName] AS [DisplayName], 
       [Extent1].[MBXServer] AS [MBXServer], 
       [Extent1].[MBXSG] AS [MBXSG], 
       [Extent1].[MBXDB] AS [MBXDB], 
       [Extent1].[MBXWarningLimit] AS [MBXWarningLimit], 
       [Extent1].[MBXSendLimit] AS [MBXSendLimit], 
       [Extent1].[MBXSendReceiveLimit] AS [MBXSendReceiveLimit], 
       [Extent1].[extensionAttribute10] AS [extensionAttribute10], 
       [Extent1].[legacyExchangeDN] AS [legacyExchangeDN], 
       [Extent1].[UserPrincipalName] AS [UserPrincipalName], 
       [Extent1].[Mail] AS [Mail], 
       [Extent1].[lastLogonTimestamp] AS [lastLogonTimestamp], 
       [Extent1].[createTimeStamp] AS [createTimeStamp], 
       [Extent1].[modifyTimeStamp] AS [modifyTimeStamp], 
       [Extent1].[altRecipient] AS [altRecipient], 
       [Extent1].[altRecipientBL] AS [altRecipientBL], 
       [Extent1].[DeletedDate] AS [DeletedDate], 
       1 AS [C1] 
       FROM [dbo].[Users] AS [Extent1] 
       INNER JOIN [dbo].[UserStats] AS [Extent2] ON [Extent1].[msExchMailboxGuid] = [Extent2].[MailboxGuid] 
       INNER JOIN [dbo].[TechContacts] AS [Extent3] ON [Extent1].[UserPrincipalName] = [Extent3].[UPN] 
      ) AS [Project1] 
    ) AS [Project1] 
WHERE [Project1].[row_number] > 120 
ORDER BY [Project1].[CompanyName] ASC 

Answer 1

答えの多くが、アドバイスはありません。まず、LinqPadを手に入れよう。クエリのチューニングを行うとき、それは非常に貴重です。第二に、私の賭けはあなたが.Joinを使った結果として巨大なクエリを得ているということです。 Linq2Entitiesは、結合を行うたびに投影（サブクエリ）を作成するという厄介な癖があります。私はLinqPadと私の質問との質の高い時間を過ごして、私が望む質問を得るまで、