如果值不为NULL,如何更新列

Question

TBL_Log如果从C#输入的值不是,我想更新表的任何列NULL.这是我的存储过程:

Alter PROCEDURE [dbo].[SP_Update_User] 
(@User_id as int,@User_Names as nvarchar(max),@End as char(8),@Start as nvarchar(max) ,@Count as int)

AS
BEGIN


UPDATE [dbo].[TBL_Log]


     SET User_Names = @User_Names
      ,[Start] = @start
      ,[End] = @End
      ,[Count] = @Count
      where User_id = @User_id



END

我试图做这项工作,但没有成功.

D1类代码:

public static DataSet Update_User(int @User_id, string @User_Names, string @End, string @Start, int @Count)
    {

        SqlConnection myConnection = new SqlConnection(strConecctionString);


        SqlDataAdapter sqlcmd = new SqlDataAdapter("SP_Update_UserData_Bot", myConnection);
        sqlcmd.SelectCommand.CommandType = CommandType.StoredProcedure;


        SqlParameter parameterID_category_ID = new SqlParameter("@User_id", SqlDbType.Int);
        parameterID_category_ID.Value = User_id;
        sqlcmd.SelectCommand.Parameters.Add(parameterID_category_ID);

        SqlParameter parameterID_Part_ID = new SqlParameter("@User_Names", SqlDbType.Int);
        parameterID_Part_ID.Value = User_Names;
        sqlcmd.SelectCommand.Parameters.Add(parameterID_Part_ID);


        SqlParameter parameterID_Series_ID = new SqlParameter("@End", SqlDbType.Char);
        parameterID_Series_ID.Value = End;
        sqlcmd.SelectCommand.Parameters.Add(parameterID_Series_ID);

        SqlParameter parameterID_Model_ID = new SqlParameter("@start", SqlDbType.NVarChar);
        parameterID_Model_ID.Value = start;
        sqlcmd.SelectCommand.Parameters.Add(parameterID_Model_ID);

        SqlParameter parameterID_Count = new SqlParameter("@Count", SqlDbType.Int);
        parameterID_Count.Value = Count;
        sqlcmd.SelectCommand.Parameters.Add(parameterID_Count);


        sqlcmd.SelectCommand.CommandTimeout = int.MaxValue;
        DataSet DS = new DataSet();
        sqlcmd.Fill(DS);


        return DS;

    }

Answer 1

这将仅更新非空值.如果值为null,则列将更新回其自己的值.

UPDATE [dbo].[TBL_Log]
SET    User_Names = isnull(@User_Names, User_Names)
     , [Start] = isnull(@start, [Start])
     , [End] = isnull(@End, [End])
     , [Count] = isnull(@Count, [Count])
where User_id = @User_id