Option Explicit
Dim DB As Database
Dim Rs As Recordset
Dim Qdf As QueryDef

Private Sub DBList1_Click()
If DBList1.Text <> "" Then



Qdf.Parameters!Name = DBList1.Text ' สลับบรรทัดนี้
Set Rs = Qdf.OpenRecordset
Set Qdf = DB.QueryDefs("SumSweet") 'สร้าง Query

'Qdf!Name = DBList1.Text
'Set Rs = Qdf.OpenRecordset
'Set Qdf = DB.QueryDefs("Myquery")

Text1.Text = Rs!SumNET
End If
End Sub

Private Sub Form_Load()
Dim SQl As String
Set DB = OpenDatabase("Nwind.mdb")
SQl = "Parameters Name text; "
SQl = SQl & "SELECT Sum(Products.UnitsinStock) as SumNet "
SQl = SQl & "From Products INNER JOIN Categories ON "
SQl = SQl & "Products.CategoryID=Categories.CategoryID "
SQl = SQl & "WHERE Categories.Categoryname=name"
'Set Qdf = DB.CreateQueryDef("SumSweet ", SQl) บรรทัดนี้ไม่ใช้ เนื่องจากได้สั่งใหม่ สร้าง Query ที่ DBList1_Click แล้ว
End Sub

Private Sub Form_Unload(Cancel As Integer)
DB.QueryDefs.Delete Qdf.Name
DB.Close
End Sub