Question

我想通过输出变量＆＃39; @ RoleID＆＃39;来阅读Scope_Identity从我指定范围标识的值。

C＃：

private static long createNewRoleInsert(ADB.Model.RolesModel roleModelObj, MSSQL sql)
{
       bool killConnection = Utils.getConnection(ref sql);

       long returnValue = 0;

       try
       {
           sql.SetSProc("[dbo].[p_Role_dfn_createNew]");
           sql.AddParam("@Title", roleModelObj.Title);
           sql.AddParam("@Description", roleModelObj.Description);
           sql.AddParam("@CreatedDate", roleModelObj.CreatedDate);

           var RoleID = sql.ExecuteNonQuery();

           if(RoleID!=0 && RoleID>0)
           {
               returnValue = RoleID;
           }
       }
       finally
       {
           if (killConnection)
               sql.Dispose();
       }

       return returnValue;
   }

存储过程：

SET ANSI_NULLS ON
SET QUOTED_IDENTIFIER ON
GO

ALTER PROCEDURE [dbo].[p_Role_dfn_createNew] 
    @Title nvarchar(250),
    @Description nvarchar(MAX) = NULL,
    @CreatedDate DateTime, 
    @RoleID bigInt OUTPUT
 AS
     SET NOCOUNT ON;
     SET XACT_ABORT ON  

     DECLARE @l_object AS SYSNAME = OBJECT_NAME(@@PROCID),
             @l_error_msg AS NVARCHAR(2000)  

  BEGIN TRY
  BEGIN TRAN
    INSERT INTO [adb_TestDb].[dbo].[Role] ([Title], [Description], [CreatedDate])
    VALUES (@Title, @Description, @CreatedDate)

    COMMIT TRAN

    SET @RoleID = SCOPE_IDENTITY(); 

    RETURN @RoleID
 END TRY
 BEGIN CATCH
    -- rollback any open/uncomitted transactions
    IF XACT_STATE() IN ( -1, 1) ROLLBACK TRANSACTION            

    -- return an error containing the object, error number and error description
    SELECT @l_error_msg = 'Error number : ' + CAST(ERROR_NUMBER()AS VARCHAR) + '. ' + ERROR_MESSAGE()          
    RAISERROR (@l_error_msg,16,1)
 END CATCH

Answer 1

ExecuteNonQuery method不返回过程的返回值，它返回受影响的行数。

要获取返回值，您需要使用ParameterDirection.ReturnValue添加参数，但这不会安全地获取@RoleID中的值，因为过程的返回值不能是{{ 1}}，它始终是bigint。

由于您已经将int作为输出参数，因此应该在命令中添加参数以获取值。例如：

@RoleID

Answer 2

您需要在C＃中添加输出参数以从存储过程中获取@RoleID的值。这是一个例子：

using System.Data.SqlClient;

using (SqlConnection conn = new SqlConnection("connectionString"))
{
    SqlCommand cmd = conn.CreateCommand();
    cmd.CommandType = System.Data.CommandType.StoredProcedure;
    cmd.CommandText = "dbo.p_Role_dfn_createNew";

    // add other parameters...

    cmd.Parameters.Add(new SqlParameter("@RoleID", SqlDbType.BigInt))
            .Direction = ParameterDirection.Output;
    cmd.ExecuteNonQuery();

    returnValue = (long)cmd.Parameters["@RoleID"].Value;
}

Answer 3

更改

RETURN @RoleID

到

SELECT @RoleID

或添加输出参数，如其他答案中所述

如何从执行的存储过程中读取C＃中的范围标识

3 个答案: