How to combine both SELECt and INSERT statement together?
I know the code below is wrong

sql = "SELECT * FROM Orderitem WHERE InvoiceNumber = '" & invoiceid & "'" & " AND ItemNumber = " & itemid
sql = sql & " AND INSERT INTO OrderItem(Quantity) VALUES(" & quantity & ")"

Invoiceid is a string and the rest of the variables are long
Ur help is deeply appreciated. Thanks