สอบถาม VB.net การแสดงข้อมูลใน DataGridview ครับ ข้อมูลไม่แสดงโปรดชี้แนะด้วยครับ

Protected Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
            Dim sCon As String = "Server=....;uid=....;database=....."


            Dim con As SqlConnection = New SqlConnection(sCon)
            Dim cmd As SqlCommand = New SqlCommand("select QstHdr.qst , avg(MRCEVD.suf) From MRCEVH INNER JOIN MRCEVD ON MRCEVH.rowid = MRCEVD.mrcevh_rowid
INNER JOIN QstHdr ON MRCEVD.seq = QstHdr.seq where Month(MRCEVH.adm_dte) = '08' and YEAR(MRCEVH.adm_dte) = '2020' and MRCEVD.seq = '1'  and QstHdr.typ = 'MRC2'
and MRCEVD.suf <> '9' group by QstHdr.rowid , QstHdr.qst")

            Dim sda As SqlDataAdapter = New SqlDataAdapter
            Try
                cmd.Connection = con : con.Open()
                sda.SelectCommand = cmd

                Dim dt As DataTable = New DataTable
                sda.Fill(dt)

                ' BIND DATABASE WITH THE GRIDVIEW.
                GridView1.DataSource = dt
                GridView1.DataBind()
            Catch ex As Exception
                Label1.Text = "error"

            End Try




        End Sub

select QstHdr.qst , avg(MRCEVD.suf) From MRCEVH INNER JOIN MRCEVD ON MRCEVH.rowid = MRCEVD.mrcevh_rowid
INNER JOIN QstHdr ON MRCEVD.seq = QstHdr.seq where Month(MRCEVH.adm_dte) = '08' and YEAR(MRCEVH.adm_dte) = '2020' and MRCEVD.seq = '1'  and QstHdr.typ = 'MRC2'
and MRCEVD.suf <> '9' group by QstHdr.rowid , QstHdr.qst