I have wished we would have an external database selector in TeamDesk
Your user is editing some record. On a field, he chooses a value from an external database which depends on the other values in the record. Ex: a company (based on a keyword and a city), a product (based on price and keyword), a law article (based on keywords)... In these cases the external database is too big or changes too often to be absorbed in TeamDesk
The selection would involve a call to the external database (a query) returning an index, a name field and some other fields helping the choice.
The selection would be done on the values stored in the TeamDesk record or, better, on the values typed in the TeamDesk record.