Update Table from Query using VBA - ms-access

Question

VBA/Macro newbie needing help with the above mentioned.
Table: Inventory
Product Value a Value b
1. Product 1 0 0
2. Product 2 0 0
3. Product 3 0 0
Query: Qry
Product Value VAL
1. Product 1 100 a
2. Product 2 200 a
3. Product 3 300 b
Result of Marco
Table: Inventory
Product Value a Value b
1. Product 1 100 0
2. Product 2 200 0
3. Product 3 0 300
Without changing the schema or thinking of alternative methods: I specifically need a macro (not an update query) to update corresponding products in table.field "Inventory.Value" with a value from query "qry" depending on whether it is in column a or column b as stated in the table.
I know that there will be an iif statement involved and a insert into but for the life of me I just cannot make it work.
EDIT: I am open to alternative ideas with the same result.
This is a watered down version of the database.

Answer 1

Thank you for the skeleton guys, it helped tremendously
This is the Macro (the fields and table names are different to my original post)
Option Compare Database
Option Explicit
Sub Opdateer()
Dim dbs As DAO.Database
Dim rst As DAO.Recordset
Dim sql As String
Set dbs = CurrentDb
sql = "SELECT Orders.Warehouse, OrderDetail.Product, OrderDetail.OrderDetailStatus, Sum(OrderDetail.Qty_mt) AS SumOfQty_mt FROM Orders INNER JOIN OrderDetail ON Orders.ID = OrderDetail.OrderNumber GROUP BY Orders.Warehouse, OrderDetail.Product, OrderDetail.OrderDetailStatus;"
Set rst = dbs.OpenRecordset(sql, dbOpenDynaset)
With rst
Do Until rst.EOF
If !OrderDetailStatus = "Allokeer" Then
sql = "UPDATE [InventoryCT] SET [StockAllocated] = " & !SumOfQty_mt & " WHERE [ProductCT] = " & !Product & " ;"
dbs.Execute (sql)
Else
sql = "UPDATE [InventoryCT] SET [StockOpgelaai] = " & !SumOfQty_mt & " WHERE [ProductCT] = " & !Product & " ;"
dbs.Execute (sql)
End If
.MoveNext
Loop
End With
rst.Close
dbs.Close
End Sub

Answer 2

You could try something like this;
Dim rst As DAO.Recordset
Dim sql As String
sql = <The sql string for your query>
Set rst = CurrentDb.OpenRecordset(sql, dbOpenDynaset)
With rst
Do Until .EOF
If !VAL = "b" Then
sql = "UPDATE Inventory SET [Value b] = " & !Value & " WHERE Product = '" & !Product "' ;"
CurrentDB.Exectute sql
End If
.MoveNext
Loop
End With