Linq实体查询添加内部连接，而不是左连接

Question

我想知道为什么INNER JOINs生成而不是左，以及为什么整个视图在连接之前选择，而不是只添加左连接视图。

我想发布一张信息表，分布在几个表。基本上我想根据日期进行搜索，并返回本月昨天，本月发生的所有事件的信息 - 无论用户选择什么。查询很长。我将DefaultIfEmpty添加到除了主表之外的所有表中，以试图获得LEFT JOIN，但它只是一团糟。

using (TransitEntities t = new TransitEntities()) 
    { 
    var charters = from c in t.tblCharters 
join v in t.tblChartVehicles.DefaultIfEmpty() 
on c.Veh 
equals v.ChartVehID 
join n in t.tblNACharters.DefaultIfEmpty() 
on c.Dpt.Substring(c.Dpt.Length - 1) 
equals SqlFunctions.StringConvert((double)n.NAID) 
join r in t.tblChartReqs.DefaultIfEmpty() 
on c.ChartReqID 
equals r.ChartReqID 
join f in t.tblCharterCustomers.DefaultIfEmpty() 
on c.Dpt 
equals (f.DptID == "NONAFF" ? SqlFunctions.StringConvert((double)f.CustID) : f.DptID) 
join d in t.tblChartReqDocs.DefaultIfEmpty() 
on c.Attach 
equals SqlFunctions.StringConvert((double)d.DocID) 
join s in t.tblChartSupAttaches.DefaultIfEmpty() 
on c.SupAttach 
equals SqlFunctions.StringConvert((double)s.DocID) 
join p in (from e in t.v_EmpData select new {e.UIN, e.First, e.Last}).DefaultIfEmpty() 
on c.TakenUIN 
equals p.UIN 
where c.BeginTime > EntityFunctions.AddYears(DateTime.Now,-1) 
select new 
{ 
    ChartID = c.ChartID, 
    Status = c.Status, 
    ... 
    Website = r.Website, 
}; 
//select today's events 
gvCharters.DataSource = charters.Where(row => (row.BeginTime.Value >= midnight && row.BeginTime.Value < midnight1)); 

这将导致非常令人费解的SQL：

SELECT 
    [Extent1].[ChartID] AS [ChartID], 
    [Extent1].[Status] AS [Status], 
    ... 
    [Join5].[Website] AS [Website], 

    FROM  [dbo].[tblCharters] AS [Extent1] 
    INNER JOIN (SELECT [Extent2].[ChartVehID] AS [ChartVehID], [Extent2].[Descr] AS [Descr] 
     FROM (SELECT 1 AS X) AS [SingleRowTable1] 
     LEFT OUTER JOIN [dbo].[tblChartVehicles] AS [Extent2] ON 1 = 1) AS [Join1] ON ([Extent1].[Veh] = [Join1].[ChartVehID]) OR (([Extent1].[Veh] IS NULL) AND ([Join1].[ChartVehID] IS NULL)) 
    INNER JOIN (SELECT [Extent3].[NAID] AS [NAID], [Extent3].[Descr] AS [Descr] 
     FROM (SELECT 1 AS X) AS [SingleRowTable2] 
     LEFT OUTER JOIN [dbo].[tblNACharter] AS [Extent3] ON 1 = 1) AS [Join3] ON ((SUBSTRING([Extent1].[Dpt], ((LEN([Extent1].[Dpt])) - 1) + 1, (LEN([Extent1].[Dpt])) - ((LEN([Extent1].[Dpt])) - 1))) = (STR(CAST([Join3].[NAID] AS float)))) OR ((SUBSTRING([Extent1].[Dpt], ((LEN([Extent1].[Dpt])) - 1) + 1, (LEN([Extent1].[Dpt])) - ((LEN([Extent1].[Dpt])) - 1)) IS NULL) AND (STR(CAST([Join3].[NAID] AS float)) IS NULL)) 
    INNER JOIN (SELECT [Extent4].[ChartReqID] AS [ChartReqID], [Extent4].[Event] AS [Event], [Extent4].[ContactName] AS [ContactName], [Extent4].[ContactPhone] AS [ContactPhone], [Extent4].[Website] AS [Website] 
     FROM (SELECT 1 AS X) AS [SingleRowTable3] 
     LEFT OUTER JOIN [dbo].[tblChartReq] AS [Extent4] ON 1 = 1) AS [Join5] ON ([Extent1].[ChartReqID] = [Join5].[ChartReqID]) OR (([Extent1].[ChartReqID] IS NULL) AND ([Join5].[ChartReqID] IS NULL)) 
    INNER JOIN (SELECT [Extent5].[CustID] AS [CustID], [Extent5].[Dpt] AS [Dpt], [Extent5].[DptID] AS [DptID] 
     FROM (SELECT 1 AS X) AS [SingleRowTable4] 
     LEFT OUTER JOIN [dbo].[tblCharterCustomers] AS [Extent5] ON 1 = 1) AS [Join7] ON ([Extent1].[Dpt] = (CASE WHEN (N'NONAFF' = [Join7].[DptID]) THEN STR(CAST([Join7].[CustID] AS float)) ELSE [Join7].[DptID] END)) OR (([Extent1].[Dpt] IS NULL) AND (CASE WHEN (N'NONAFF' = [Join7].[DptID]) THEN STR(CAST([Join7].[CustID] AS float)) ELSE [Join7].[DptID] END IS NULL)) 
    INNER JOIN (SELECT [Extent6].[DocID] AS [DocID], [Extent6].[FileName] AS [FileName] 
     FROM (SELECT 1 AS X) AS [SingleRowTable5] 
     LEFT OUTER JOIN [dbo].[tblChartReqDocs] AS [Extent6] ON 1 = 1) AS [Join9] ON ([Extent1].[Attach] = (STR(CAST([Join9].[DocID] AS float)))) OR (([Extent1].[Attach] IS NULL) AND (STR(CAST([Join9].[DocID] AS float)) IS NULL)) 
    INNER JOIN (SELECT [Extent7].[DocID] AS [DocID], [Extent7].[FileName] AS [FileName] 
     FROM (SELECT 1 AS X) AS [SingleRowTable6] 
     LEFT OUTER JOIN [dbo].[tblChartSupAttach] AS [Extent7] ON 1 = 1) AS [Join11] ON ([Extent1].[SupAttach] = (STR(CAST([Join11].[DocID] AS float)))) OR (([Extent1].[SupAttach] IS NULL) AND (STR(CAST([Join11].[DocID] AS float)) IS NULL)) 
    INNER JOIN (SELECT [Extent8].[First] AS [First], [Extent8].[Last] AS [Last], [Extent8].[UIN] AS [UIN] 
     FROM (SELECT 1 AS X) AS [SingleRowTable7] 
     LEFT OUTER JOIN (SELECT 
      [v_EmpData].[First] AS [First], 
      [v_EmpData].[Last] AS [Last], 
      [v_EmpData].[Legal] AS [Legal], 
      [v_EmpData].[Name] AS [Name], 
      [v_EmpData].[Email] AS [Email], 
      [v_EmpData].[UIN] AS [UIN], 
      [v_EmpData].[UserNM] AS [UserNM], 
      [v_EmpData].[Worker] AS [Worker], 
      [v_EmpData].[SUPERVISORNUM] AS [SUPERVISORNUM], 
      [v_EmpData].[Supervisor] AS [Supervisor], 
      [v_EmpData].[EmpArea] AS [EmpArea], 
      [v_EmpData].[Title] AS [Title], 
      [v_EmpData].[FullName] AS [FullName], 
      [v_EmpData].[HireDate] AS [HireDate], 
      [v_EmpData].[WORKERTYPENM] AS [WORKERTYPENM], 
      [v_EmpData].[Birth] AS [Birth], 
      [v_EmpData].[HOMESTREET] AS [HOMESTREET], 
      [v_EmpData].[HOMECITY] AS [HOMECITY], 
      [v_EmpData].[HOMEZIP] AS [HOMEZIP], 
      [v_EmpData].[HOMESTATE] AS [HOMESTATE], 
      [v_EmpData].[PicID] AS [PicID], 
      [v_EmpData].[WorkPhone] AS [WorkPhone], 
      [v_EmpData].[HomePhone] AS [HomePhone], 
      [v_EmpData].[WorkCellPhone] AS [WorkCellPhone] 
     FROM [dbo].[v_EmpData] AS [v_EmpData]) AS [Extent8] ON 1 = 1) AS [Join13] ON ([Extent1].[TakenUIN] = [Join13].[UIN]) OR (([Extent1].[TakenUIN] IS NULL) AND ([Join13].[UIN] IS NULL)) 
WHERE ([Extent1].[BeginTime] > (DATEADD (year, -1, SysDateTime()))) 
    AND ('C' <> [Extent1].[Status]) 
    AND ([Extent1].[BeginTime] >= '11/28/2012 12:00:00 AM') 
    AND ([Extent1].[BeginTime] < '11/29/2012 12:00:00 AM') 

这是我原来的SQL查询看起来像什么，我希望它会更接近：

SELECT 
    ChartID, 
    c.Status, 
    ... 
    r.Website As Website, 

FROM tblChartersNew c 
    LEFT JOIN (SELECT [Dpt],[DptID] FROM [DRVRDiscipline].[dbo].[tblCharterCustomers] Where Valid=1 and DptID <> 'NONAFF' UNION SELECT Dpt, CONVERT(nvarchar,CustID) AS DptID FROM [DRVRDiscipline].[dbo].[tblCharterCustomers] Where Valid=1 and DptID = 'NONAFF') f 
    ON RTRIM(c.Dpt) = f.DptID LEFT JOIN [tskronos].WfcSuite.dbo.VP_ALLPERSONV42 p ON p.PersonNUM = c.TakenUIN 
    LEFT JOIN tblChartVehicles v ON v.ChartVehID = c.Veh 
    LEFT JOIN tblNACharter n ON CAST(n.NAID AS varchar) = RIGHT(c.Dpt, LEN(c.Dpt)-1) 
    LEFT JOIN tblChartReq r 
    ON r.ChartReqID = c.ChartReqID 
WHERE CONVERT(datetime,CONVERT(char(10),c.BeginTime,101)) = (SELECT TOP 1 CONVERT(datetime,CONVERT(char(10),BeginTime,101)) from tblChartersNew WHERE CONVERT(datetime,CONVERT(char(10),BeginTime,101)) >= CONVERT(datetime,CONVERT(char(10),GETDATE(),101)) ORDER BY BeginTime) 
    AND NOT c.ChartReqID IS NULL 
ORDER BY BeginTime, ISNULL(f.Dpt,c.Dpt) 

我也在视图中添加一个Select New以避免在我只需要三个时选择所有的列，但它似乎没有什么区别。不添加LEFT JOIN v_EmpData，而是添加LEFT OUTER JOIN，然后选择视图中的所有列。它似乎忽略了Select New。

我真的很想过渡到使用Linq的实体为我的大部分查询，因为intellisense使得它更容易确保它是正确的，并有查询的变化，而不必为每个单独的功能，但也许我需要坚持使用普通的旧SQL。我知道这足以让一团糟。有什么建议么？

Answer 1

适用于您需要的复杂查询。

我会建议看看FunctionImport。

MSDN Function Import

这将节省您创建一个LINQ的头痛，这将是1：1到你的预期生成的SQL。