Question

我正在研究重写一个在我的代码中返回输出参数的存储过程。为什么我这样做是因为我想要一个本地存储过程而不必从MSSQL调用存储过程。

这可能吗？如果是这样，那怎么样？

Answer 1

我已经研究过LINQ to Entities并开始意识到对查询的控制很少。我需要找到更多权威信息，但是从使用真实存储过程和使用多个查询开始，由于MSSQL中包含的预构建项目和大量（意味着数十万）记录，实际存储过程会更有效。的SP。当我们希望从站点的前端传输小规模数据而不是使用存储过程时，我正在使用此问题作为未来项目的参考。

此链接是我用来编写原始SQL代码的链接。我正在使用原始调用，所以我可以返回字符串变量。
http://www.entityframeworktutorial.net/EntityFramework4.3/raw-sql-query-in-entity-framework.aspx

我的存储过程的草稿如下：

在查看此答案时，我使用//作为易读性目的。使用此代码时请使用--。

CREATE PROCEDURE [dbo].[spSomething] 
        @FirstName  varchar(25),
        @LastName   varchar(25),
        @UserID     varchar(25),
        @RentalManID    varchar(25),
        @BranchAreaNum  varchar(25),
        @ReturnVal varchar(1) = '0' output

WITH RECOMPILE
AS
BEGIN   

SET NOCOUNT ON;
DECLARE @CheckTblUserAdded varchar(25)
DECLARE @CheckTblUser varchar(25)
// ReturnVal = 0 means it failed to add user to table
// ReturnVal = 1 means it succeded in adding user to table
// ReturnVal = 2 means the user has already been added to the table

// Search for user inside tblUserAdded
SELECT @CheckTblUserAdded = [Window ID] FROM dbo.tblUserAdded WHERE [Window ID] = @UserID AND 
                                                           [Rentalman ID] = @RentalManID AND 
                                                           [BranchAreaNum] = @BranchAreaNum AND 
                                                           [FirstName] = @FirstName AND
                                                           [LastName] = @LastName
// Search for user inside tblUser
SELECT @CheckTblUser = [UserID] FROM dbo.tblUser WHERE [UserID] = @UserID AND
                                                           [RentalManID] = @RentalManID

// Add new user if not found in either tblUserAdded or tblUser
// and if the users windows id and rentalmanid are not the same
IF (ISNULL(@CheckTblUserAdded, '') = '') AND (ISNULL(@CheckTblUser, '') = '') AND (@UserID <> @RentalManID)
BEGIN
    // Do something here
    SELECT @ReturnVal = '1' // as success
END
// Record attempt of adding an existing user
ELSE
BEGIN
    // Do something here
    SELECT @ReturnVal = '2' // already exists
END

SELECT @ReturnVal

END

这是我控制器内部的原始SQL版本：

public ActionResult Create([Bind(Include="Window_ID,Rentalman_ID,BranchAreaNum,FirstName,LastName")] tblUserAdded tbluseradded)
    {
        if (ModelState.IsValid)
        {
            if (tbluseradded.Window_ID == tbluseradded.Rentalman_ID)
            {
                System.Diagnostics.Debug.WriteLine("The user should already have access since the user's Windows ID and RentalMan ID are the same. Contact IAUnit for help on the issue");
            }
            else
            {
                // Rewrite stored procedure in form of raw SQL
                string returnVal = "0";
                // This will check to see if a user has already been added to tblUser and tblUserAdded
                string checkTblUserAdded = db.Database.SqlQuery<string>("SELECT [Window ID] FROM dbo.tblUserAdded WHERE " + 
                    "[Window ID] = '" + tbluseradded.Window_ID + "' AND " +
                    "[Rentalman ID] = '" + tbluseradded.Rentalman_ID + "' AND " +
                    "[BranchAreaNum] = '" + tbluseradded.BranchAreaNum + "' AND " +
                    "[FirstName] = '" + tbluseradded.FirstName + "' AND " +
                    "[LastName] = '" + tbluseradded.LastName + "'").FirstOrDefault<string>();
                string checkTblUser = db.Database.SqlQuery<string>("SELECT [UserID] FROM dbo.tblUser WHERE " +
                    "[UserID] = '" + tbluseradded.Window_ID + "' AND " +
                    "[RentalManID] = '" + tbluseradded.Rentalman_ID + "'").FirstOrDefault<string>();
                // Add new user if not found in either tblUserAdded or tblUser
                if (checkTblUser == null && checkTblUserAdded == null)
                {
                    System.Diagnostics.Debug.WriteLine("We can add the user now! We did it!");
                    returnVal = "1";
                    // Do something here
                }
                else
                {
                    System.Diagnostics.Debug.WriteLine("This user already has access");
                    returnVal = "2";
                    // Do something here
                }
                System.Diagnostics.Debug.WriteLine("The return value is: " + returnVal);
                System.Diagnostics.Debug.WriteLine("Please break here!");
                db.SaveChanges();
            }
            return RedirectToAction("Index");
        }

        return View(tbluseradded);
    }

我确信有一种更好的方法可以通过将实际的原始SQL放在数据访问层中来编码，但我将其用于仅供参考。

编写类似于我的MVC项目中的存储过程的SQL代码

1 个答案: