Question

我使用以下代码在给定用户输入的情况下运行存储过程。如果输入有效并且不会有重复记录，则存储过程会更新某些表如果输入无效或该记录已存在，则存储过程返回分配给变量消息的OUT参数的值。如何在屏幕上显示消息的值？ Messabebox将是理想的，但找不到应该从哪里调用它。

partial void MyStorProc_Inserting(MyStorProcOperation entity)
{
    using (SqlConnection connection = new SqlConnection())
    {
        string connMyDB = this.DataWorkspace.MyDB.Details.Name;
        connection.ConnectionString = ConfigurationManager.ConnectionStrings[connMyDB].ConnectionString;

        string proc = "[MyDB].[dbo].[szMyStorProc]";
        using (SqlCommand command = new SqlCommand(proc, connection))
        {
            command.CommandType = CommandType.StoredProcedure;
            command.Parameters.Add(new SqlParameter("@Uname", entity.Uname));
            command.Parameters.Add(new SqlParameter("@BU", entity.BU));

            SqlParameter output = new SqlParameter();
            output.ParameterName = "@ResultDescription";
            output.SqlDbType = System.Data.SqlDbType.VarChar;
            output.Direction = ParameterDirection.Output;
            output.Size = 256;
            command.Parameters.Add(output);

            connection.Open();
            command.ExecuteNonQuery();

            string message = output.Value.ToString();
        }
    }

    this.Details.DiscardChanges();
}

存储过程有点像这样：

CREATE PROCEDURE [dbo].[szMyStorProc] 
-- Add the parameters for the stored procedure here
@Uname varchar(50) = '', 
@BU varchar(50) = '',
@ResultDescription varchar(256)= ''  OUTPUT

AS
BEGIN
-- SET NOCOUNT ON added to prevent extra result sets from
-- interfering with SELECT statements.
SET NOCOUNT ON;

    -- Insert statements for procedure here
DECLARE @EmployeeID INT
DECLARE @BUID INT
SELECT @EmployeeID = ID FROM tEmployee WHERE Uname = @Uname
IF @EmployeeID IS NULL 
BEGIN
    SELECT @ResultDescription = 'User name not found'
    PRINT @ResultDescription
END
ELSE
        ... 
        ...
    END
GO

有没有办法让lightswitch屏幕显示从存储过程返回的参数？

0 个答案: