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从ADO.NET存储过程中获取返回值

ado.net c#

WebMonster · 技术社区 · 16 年前

我有一个存储过程,它在插入后返回唯一标识符 @@identity @RETURN_VALUE = [identifier] .

在我的代码中,我添加了一个名为 @RETURN_VALUE ExecuteNonQuery()

 ALTER PROCEDURE dbo.SetAuction
 (
  @auctionID int,
  @itemID int,
  @auctionType tinyint,
  @reservationPrice int,
  @maxPrice int,
  @auctionEnd datetime,
  @auctionStart datetime,
  @auctionTTL tinyint,
  @itemName nchar(50),
  @itemDescription nvarchar(MAX),
  @categoryID tinyint,
  @categoryName nchar(50)
 ) AS
 IF @auctionID <> 0
  BEGIN
   BEGIN TRAN T1
   
   UPDATE Auction
   SET  AuctionType   = @auctionType,
     ReservationPrice = @reservationPrice,
     MaxPrice    = @maxPrice,
     AuctionEnd    = @auctionEnd,
     AuctionStart   = @auctionStart,
     AuctionTTL    = @auctionTTL
   WHERE AuctionID    = @auctionID;
   
   UPDATE Item
   SET
    ItemName  = @itemName,
    ItemDescription = @itemDescription
   WHERE
    ItemID = (SELECT ItemID FROM Auction WHERE AuctionID = @auctionID);
   
   COMMIT TRAN T1
   
   RETURN @auctionID
  END
 ELSE
  BEGIN
   BEGIN TRAN T1
    INSERT INTO Item(ItemName, ItemDescription, CategoryID)
    VALUES(@itemName, @itemDescription, @categoryID);
    
    INSERT INTO Auction(ItemID, AuctionType, ReservationPrice, MaxPrice, AuctionEnd, AuctionStart, AuctionTTL)
    VALUES(@@IDENTITY,@auctionType,@reservationPrice,@maxPrice,@auctionEnd,@auctionStart,@auctionTTL);
   COMMIT TRAN T1
   RETURN @@IDENTITY
  END

C代码

cmd.CommandText = cmdText;
SqlParameter retval = new SqlParameter("@RETURN_VALUE", System.Data.SqlDbType.Int);
retval.Direction = System.Data.ParameterDirection.ReturnValue;
cmd.Parameters.Add(retval);
cmd.Parameters.AddRange(parameters);
cmd.Connection = connection;

connection.Open();
cmd.ExecuteNonQuery();

return (int)cmd.Parameters["@RETURN_VALUE"].Value;

5 回复 | 直到 5 年前

Tim Cooper 14 年前

刚试过我的盒子,这对我很有用:

DROP PROCEDURE TestProc;
GO
CREATE PROCEDURE TestProc
AS
   RETURN 123;
GO

        string cnStr = "Server=.;Database=Sandbox;Integrated Security=sspi;";
        using (SqlConnection cn = new SqlConnection(cnStr)) {
            cn.Open();
            using (SqlCommand cmd = new SqlCommand("TestProc", cn)) {
                cmd.CommandType = CommandType.StoredProcedure;
                SqlParameter returnValue = new SqlParameter();
                returnValue.Direction = ParameterDirection.ReturnValue;
                cmd.Parameters.Add(returnValue);

                cmd.ExecuteNonQuery();
                Assert.AreEqual(123, (int)returnValue.Value);
            }
        }

WebMonster 16 年前

我解决了这个问题: 你必须把 SqlCommand.CommandType CommandType.StoredProcedure 以获取返回值和/或输出参数。我还没有找到任何关于这个的文档,但现在一切都正常了。

Marc Gravell 16 年前

你知道你的价值吗 EXEC SCOPE_IDENTITY()

所以改变一下:

COMMIT TRAN T1
RETURN @@IDENTITY

收件人:

SET @auctionID = SCOPE_IDENTITY()
COMMIT TRAN T1
RETURN @auctionID

)我也会换另一个 @@IDENTITY 到 作用域\标识() )

作为次要优化,您还可以使用:

return (int)retval.Value;

但事情的这一面从我所看到的情况来看,我已经“按原样”工作了(因此我将重点放在TSQL上)。

Prashant Gupta 13 年前

有些人也可以使用这种简单而简短的方法来计算SP的返回值

在SQL中:

Create Table TestTable 
(
 Int Id
)

CREATE PROCEDURE Proc_TestProc
 @Id
 AS
   Begin
     Set NOCOUNT ON  //Use this line if you don't want to return any message from SQL

     Delete from TestTable where Id = @Id
     return 1

     Set NOCOUNT OFF //NOCOUNT OFF is Optional for NOCOUNT ON property
   End

在C中#

using (SqlConnection conn = new SqlConnection(System.Configuration.ConfigurationManager.ConnectionStrings["TestConnectionString"].ToString()))
using (SqlCommand cmd = new SqlCommand("Proc_TestProc", conn))
{
 cmd.CommandType = CommandType.StoredProcedure;

 cmd.Parameters.AddWithValue("@Id", 1);
 var returnParameter = cmd.Parameters.Add("@ReturnVal", SqlDbType.Int);
 returnParameter.Direction = ParameterDirection.ReturnValue;

 conn.Open();
 cmd.ExecuteNonQuery();
 var result = returnParameter.Value;
}

还可以使用以下命令检查SQL中的返回值:

DECLARE @return_status int;
EXEC @return_status = dbo.[Proc_TestProc] 1;
SELECT 'Return Status' = @return_status;
print 'Returned value from Procedure: ' + Convert(varchar, @return_status); // Either previous or this line both will show you the value of returned value

dreamafon 6 年前

您可以使用以前在普通查询中使用的标准方式,但在Sql命令中,您必须在存储过程名称之前写入EXEC,并且不要像这样使用commandtype:

 SqlConnection con = new SqlConnection(["ConnectionString"])
    SqlCommand com = new SqlCommand("EXEC _Proc @id",con);
    com.Parameters.AddWithValue("@id",["IDVALUE"]);
    con.Open();
    SqlDataReader rdr = com.ExecuteReader();
    ArrayList liste = new ArrayList();
    While(rdr.Read())
    {
    liste.Add(rdr[0]); //if it returns multiple you can add them another arrays=> liste1.Add(rdr[1]) ..
    }
    con.Close();