Returning true/false in a boolean function

[WickedFooker]

I am trying to say if a teacher is already teaching 3 classes flag it by returning a true if so, or a false if not. I have it counting the rows (or so I thought), but it is saying the way I did it is not correct. That Tables[0] is invalid.

private bool ValidateTeacher(string TeacherID, String Semester)
{
// Populate Room and add Please Select
string path = Server.MapPath("eAcademy_DB.mdb");
string connectionString = "PROVIDER=Microsoft.Jet.OLEDB.4.0;Data Source=" + path;
string commandText = "SELECT COUNT(*) FROM tblClass WHERE emp_ID=? and sem_Time=?";

    var ds6 = new DataSet();

    using (var connection = new OleDbConnection(connectionString))
    using (var command = new OleDbCommand(commandText, connection))
    {
        // OleDbCommand uses positional, rather than named, parameters.
        // The parameter name doesn't matter; only the position.
      

        var adapter = new OleDbDataAdapter(command);
        if (ds6.Tables\[0\].Rows.Count > 3)
        {
            return false;
        }
        else return true;
        
    }
}

[Joshua Omundson]

You have to fill the DataSet before you read from it.

adapter.Fill(ds6, "Teacher");

[Muhammed Yaseen]

You are just creating an adapter and a dataset. You have fill the dataset using the adapter.

adapter.Fill(ds6);

or

adapter.Fill(ds6, "");