Unanswered: lookup 2 values to return another in update query
I am new to this forum so bear with me.
I have 2 tables: fuel conversion table that has 4 fields: id, fuel type, fuel unit and conversion rate
the second table is an input form that has fuel type, fuel unit (these 2 fields are populated by query from conversion table) and conversion rate.
I need to run an update query on the input table to populate the conversion field after looking up the fuel type and then the unit measure.
I have spent about 10 hours on this and nothing is working. it sounds simple but the second half of the lookup is not working (so it finds the fuel type but not the corresponding unit).