VB.NET/SQL รบกวนดูโค้ดให้หน่อยค่ะ จะใส่ Group by แต่มัน error ค่ะ

Dim strSQL As String = ""
        'Position-Trained Query
        strSQL = "SELECT DISTINCT PositionPerson.PositionId,Training.CourseID, Course.Title, TrainingResult.PersonId, Personnel.TName, Personnel.TLastname,"
        'strSQL &= " PositionPerson.PositionId, Description.Dept,"
        strSQL &= " Description.Dept,"
        strSQL &= " TR_ISO_Type.ISO_Type_Description, TrainingResult.Remarks,Training.TrainingNo,Training.TrainedDate,Training.FinishDate"
        strSQL &= " FROM Description INNER JOIN ((((Course INNER JOIN (Training INNER JOIN TrainingResult ON Training.TrainingNo = TrainingResult.TrainingNo)"
        strSQL &= " ON Course.Course_Id = Training.CourseID) INNER JOIN Personnel ON TrainingResult.PersonId = Personnel.PersonId) INNER JOIN TR_ISO_Type ON Course.ISO_Type_Id = TR_ISO_Type.ISO_Type_Id)"
        strSQL &= " INNER JOIN PositionPerson ON Personnel.PersonId = PositionPerson.PersonId) ON Description.PositionId = PositionPerson.PositionId "

If cboSearch.SelectedIndex = 0 Then 'รหัสหลักสูตร (Course Id)
            strSQL &= " AND ((Course.Course_Id) LIKE '%" & txtSearch.Text & "%')"
        ElseIf cboSearch.SelectedIndex = 1 Then 'รหัสพนักงาน (Person Id)
            strSQL &= " AND ((Personnel.PersonId) LIKE '%" & txtSearch.Text & "%')"
        ElseIf cboSearch.SelectedIndex = 2 Then 'ชื่อพนักงาน
            strSQL &= " AND ((Personnel.TName) LIKE '%" & txtSearch.Text & "%')"
        ElseIf cboSearch.SelectedIndex = 3 Then 'นามสกุลพนักงาน
            strSQL &= " AND ((Personnel.TLastname) LIKE '%" & txtSearch.Text & "%')"
        ElseIf cboSearch.SelectedIndex = 4 Then 'รหัสตำแหน่งพนักงาน (Position Id)
            'strSQL &= " AND ((PositionPerson.PositionId) LIKE '%" & txtSearch.Text & "%')"
        ElseIf cboSearch.SelectedIndex = 5 Then 'แผนกงานของพนักงาน (Dept.)
            strSQL &= " AND ((Description.Dept) LIKE '%" & txtSearch.Text & "%')"
        End If

strSQL &= " AND ((TrainingResult.Remarks)='Succeed')"
        strSQL &= " AND ((Course.PositionNeed)='1')"
        strSQL &= " AND ((Personnel.InactiveReason) Is Null)"
        strSQL &= " AND ((PositionPerson.Main)=FALSE)"           
        strSQL &= " )"
        strSQL &= "ORDER BY Training.CourseID ASC,"

        strSQL &= "GROUP BY Training.Training.TrainingNo" 'จะใส่แบบนี้ค่ะ แต่ใส่แล้วมัน error