Question

im pretty new in sql coding and i couldent find a solution on internet, heres my code:

CREATE PROCEDURE GET_SAMEDATE (@FileName VARCHAR(50))
AS
    /* SET NOCOUNT ON */
    SELECT Hash
    FROM   Beamer.PackageDetailFile A(NOLOCK)
           INNER JOIN(SELECT FileName,
                             MAX(Date) MaxDate
                      FROM   Beamer.PackageDetailFile(NOLOCK)
                      GROUP  BY FileName)B
             ON B.FileName = A.FileName
                AND A.Date = B.MaxDate
    WHERE  FileName = @FileName 

what i want to do is i want to compare the FileName with the filename i obtain from a c# class

And im also getting “Ambiguous column name ‘FileName’ “

* ambigious column name is resolved but still i cannot get the FileName from the other class to compare if they have the same filename

the c# code

SqlConnection myConnection = new SqlConnection(myConnectionString);

 SqlCommand myCommand = new SqlCommand("dbo.GET_SAMEDATE", myConnection );
 myCommand.CommandType = CommandType.StoredProcedure;
 try
 {
    myConnection.Open();
    SqlDataReader sdr = myCommand.ExecuteReader();

    while (sdr.Read())       
    {                   
        string h = (string)sdr.GetString(0);                     

        if (hash != h)
        {
           exists = true;
        }

       sdr.Read();
    }

Answer 1

You would need to specify the table prefix in the WHERE clause. You don’t need the join on the sub query with GROUP BY anyway though. It can be done much simpler.

CREATE PROCEDURE GET_SAMEDATE (@FileName VARCHAR(50))
AS
    SET NOCOUNT ON;

    SELECT TOP 1 WITH TIES Hash
    FROM   Beamer.PackageDetailFile
    WHERE  FileName = @FileName
    ORDER  BY Date DESC