如何在存儲過程中獲得計算列值

Question

我正在使用ASP.NET 4.0，C＃和SQL Server 2008 R2。我從網頁中的用戶處獲取UserName，以便存儲在SQL表User_Info2中。使用SQL Server 2008功能「計算列」，我使用存儲過程爲每個Insert自動生成Vendor_ID。在按鈕單擊時，在插入記錄後，我想用Vendor_ID顯示消息，那麼請任何人告訴我如何從存儲過程獲取Vendor_ID列？

CREATE TABLE User_Info2 
    ( SNo int Identity (2000,1) , 
     Vendor_ID AS 'VEN' + CAST(SNo as varchar(16)) PERSISTED PRIMARY KEY, 
     UserName VARCHAR(30) NOT NULL 
    ) 

存儲過程

ALTER PROCEDURE [dbo].[usp_User_Info2] @UserName VARCHAR(30) 
    AS 
    BEGIN 
     SET NOCOUNT ON; 

     INSERT INTO User_Info2 (UserName) VALUES (@UserName) 
    END 

C＃代碼：

protected void BtnUserNext_Click(object sender, EventArgs e) 
{  
    SqlConnection SqlCon = new SqlConnection(GetConnectionString()); 
    SqlCommand cmd = new SqlCommand(); 
    cmd.CommandType = CommandType.StoredProcedure; 
    cmd.CommandText = "usp_User_Info2"; 
    cmd.Parameters.Add("@UserName", SqlDbType.VarChar).Value = txtUserName.Text.Trim();  
    cmd.Connection = SqlCon;  
    try 
    {  
    SqlCon.Open(); 
    cmd.ExecuteScalar(); 
    } 
    finally 
    { 
    string url = "../CompanyBasicInfo.aspx?Parameter=" + Server.UrlEncode ("+ Vendor_ID +"); 
    ClientScript.RegisterStartupScript(this.GetType(),"callfunction", 
    "alert('Login created successfully for "+ Vendor_ID +"'); 
    window.location.href = '" + url + "';", true); 
    SqlCon.Close();  
    }  
} 

Answer 1

您可以輸出使用OUTPUT條款，然後插入值讀取它，當你執行存儲過程：

ALTER PROCEDURE [dbo].[usp_User_Info2] @UserName VARCHAR(30) 
AS 
BEGIN 
    SET NOCOUNT ON; 

    INSERT INTO User_Info2 (UserName) 
    OUTPUT Inserted.Vendor_ID 
    VALUES (@UserName) 
END 

，並在C＃調用代碼：

object spResult; 
    string vendorID; 

    try 
    {  
    SqlCon.Open(); 
    spResult = cmd.ExecuteScalar(); 

    if(spResult != null) // check to make sure you got something back! 
    { 
     vendorID = spResult.ToString(); 
    }   
    } 

Answer 2

也ü可以這樣做

select top(1) Vendor_ID from User_Info2 order by SNo desc 

Answer 3

你可以試試這個

ALTER PROCEDURE [dbo].[usp_User_Info2] @UserName VARCHAR(30) 
AS 
BEGIN 
    SET NOCOUNT ON; 

    declare @Id int 

    INSERT INTO User_Info2 (UserName) VALUES (@UserName) 

    SET @Id = Scope_Identity() 

    SELECT Vendor_ID From User_Info2 WHERE SNo = @Id 
END 

C＃

try 
{  
    SqlCon.Open(); 
    string VendorID = cmd.ExecuteScalar() as string; 
} 

Answer 4

你可以獲取當前插入行的幫助的SCOPE_IDENTITY()

SET @SNo = SCOPE_IDENTITY() 

及以下插入查詢可以執行對@SNo

選擇查詢，因此，這將是：

ALTER PROCEDURE [dbo].[usp_User_Info2] 
(
    @UserName VARCHAR(30), 
    @SNo int, 
    @Vendor_ID VARCHAR(50) OUTPUT 
) 
AS 
BEGIN 
    SET NOCOUNT ON; 

    INSERT INTO User_Info2 (UserName) VALUES (@UserName) 
    SET @SNo = Scope_Identity() 


    select @Vendor_ID as Vendor_ID from User_Info2 where SNo = @SNo 

END 

編輯：

SqlParameter[] param= new SqlParameter[1]; 

param[0] = new SqlParameter("@Vendor_ID", 0); 
param[0].Direction = ParameterDirection.Output; 

// Here there will be a Stored Procedure Call 

int VendorID = Convert.ToInt32(param[0].Value); 

所以現在你會@Vendor_ID這是一個Output變量。