二表SUM后合并，为何得出错误结果？

Private Sub Command2_Click()
'填写表头
    MSHFlexGrid3.Cols = 5
    MSHFlexGrid3.Col = 1
    MSHFlexGrid3.Row = 0
    MSHFlexGrid3.Text = "编号"
    MSHFlexGrid3.Col = 2
    MSHFlexGrid3.Text = "规格"
    MSHFlexGrid3.Col = 3
    MSHFlexGrid3.Text = "已生产"
    MSHFlexGrid3.Col = 4
    MSHFlexGrid3.Text = "已包装"
   
    Set cn = New ADODB.Connection
    cn.Open "Provider=Microsoft.Jet.OLEDB.4.0;Data Source= " & App.Path & "\rc.mdb"
   '//////////////////////////
   Set rs1 = New ADODB.Recordset
        rs1.Open "select 编号,规格,sum(数量) as 已生产 from sc group by  编号,规格 ", cn, adOpenStatic, adLockOptimistic
        If rs1.RecordCount > 0 Then
        Set MSHFlexGrid1.DataSource = rs1
        
        MSHFlexGrid3.Rows = rs1.RecordCount + 1   '设置表格行数
        
    Else
         Exit Sub
    End If
   '///////////////////////////
   Set rs2 = New ADODB.Recordset
        rs2.Open "select 编号,sum(数量) as 已包装 from bz group by  编号 ", cn, adOpenStatic, adLockOptimistic
        If rs2.RecordCount > 0 Then
        Set MSHFlexGrid2.DataSource = rs2
    Else
         Exit Sub
    End If
    '///////////////////////////
    Dim i As Integer, j As Integer
    Do While Not rs1.EOF
        i = i + 1
        MSHFlexGrid3.Row = i
        For j = 0 To 2
            MSHFlexGrid3.Col = j + 1
            MSHFlexGrid3.Text = rs1(j)
            
        Next
        MSHFlexGrid3.Col = 4
        rs2.MoveFirst
        Do While Not rs2.EOF
            If rs1(0) = rs2(0) Then
                MSHFlexGrid3.Text = rs2(1)
                Exit Do
               Else
                MSHFlexGrid3.Text = 0
            End If
            rs2.MoveNext
        Loop
        
        rs1.MoveNext
   
    Loop

  
    rs1.Close
    rs2.Close

    cn.Close
    Set rs1 = Nothing
    Set rs2 = Nothing

    Set cn = Nothing
End Sub