Update query gives odd message

[David]

I've written my first ever update query but when I try to
run it, it says 'operation must use an updatable query'. I
do not know what this means. Here is the query:

Update ChangeRequest
Set RequestType = (Select RequestTypeID from
RequestTypeConv where RequestTypeCode =
ChangeRequest.RequestTypeID);

 

[Duane Hookom]

Try:
Update ChangeRequest
Set RequestType = DLookup("RequestTypeID", "RequestTypeConv",
"RequestTypeCode =" & RequestTypeID);
The above assumes a numeric field of RequestTypeCode. If it is text, try:
Set RequestType = DLookup("RequestTypeID", "RequestTypeConv",
"RequestTypeCode =""" & RequestTypeID & """");