将复杂的 SQL 查询转换为 LINQ

如何解决将复杂的 SQL 查询转换为 LINQ

请查看我下面的 sql 查询，我需要在 LINQ 中转换它，我尝试了多种方法，但无法正常工作。

这是我的 sql 查询

SELECT        SL_Transactions.TransID,SL_Trans_Details.TransDetID AS Expr2,SL_Transactions.PAY,SL_Transactions.Allocated,SL_Debits.INV,SL_Debits.ADR,SL_Debits.RFD
FROM            SL_Trans_Details AS SL_DebitDetails LEFT OUTER JOIN
                         SL_Transactions AS SL_Debits ON SL_DebitDetails.TransID = SL_Debits.TransID RIGHT OUTER JOIN
                         SL_Trans_Allocation_History ON SL_DebitDetails.TransDetID = SL_Trans_Allocation_History.DebitTransDetID RIGHT OUTER JOIN
                         SL_Transactions INNER JOIN
                         SL_Trans_Details ON SL_Transactions.TransID = SL_Trans_Details.TransID ON SL_Trans_Allocation_History.CreditTransDetID = SL_Trans_Details.TransDetID
WHERE        (SL_Transactions.PAY = 254)

我已经尝试过以下方法但尚未解决。 C#类

public class InvoiceReturnValue
        { 
            public int TransID { get; set; }
            public int? INV { get; set; }
            public int? RFD { get; set; }
        }

LINQ 查询

var Invoiedata = from SL_DebitDetails in Db.SL_Trans_Details
                             join SL_Debits in Db.SL_Transactions on SL_DebitDetails.TransID equals SL_Debits.TransID
                             join SL_Trans_All in Db.SL_Trans_Allocation_History on SL_DebitDetails.TransDetID equals SL_Trans_All.DebitTransDetID
                             join SL_Trans in Db.SL_Transactions on SL_DebitDetails.TransID equals SL_Trans.TransID
                             where SL_Trans.PAY == 250
                             select new InvoiceReturnValue
                             {
                                 TransID= SL_Trans.TransID,INV= SL_Debits.INV,RFD= SL_Debits.RFD
                             };

表关系如下。