Lookup Function

[jscooper]

I finally started playing with the Lookup function and, I'm embarrassed to admit, I'm a bit confused. What capability does this provide that's not already available with a regular lookup or an auto-enter calculation? A field set as a calculation field with the function Lookup("Relatedtable::value") seems to have the same result as making the field a regular lookup (and locking it to prevent overwriting the looked-up value), or auto entering the calculation "relatedtable::value" (and locking the field).

All result in an indexible field that need to be manually tripped to repull changed values either by triggering a relookup or, in the case of an auto-enter calculation, manually changing the value or adding the match field to the auto-enter calculation to have it update when the match field changes. Why would I want to use this function instead of using a regular lookup field or auto-enter calculation?

I must be missing something obvious, but I just don't see it.

Thanks,

Jeff

[Ugo DI LUCA]

Hi Jeff,

The main benefit of Lookup ( ) vs an auto-entered calculation involving a related field is with situations where you'd have needed more than one lookup fields with prior versions with one calculation "choosing" the correct result.

If a relationship is updated, the calc involving a Lookup( ) will refresh where the pure related won't.

ex : Price being either a List Price, a Discounted Price due to Promotions, a discounted price due to Customer Price Grid, etc.,

FM6 will need 3 lookups and one calc to pick one of the 3. FM7 needs one calculation only.

When it can be chained, depending upon your own rules, it gets VERY powerful.

Lookup(CustomerSpecialGrid::Price;Lookup(Promotions::Price;Lookup(CatalogPrice::Price)))

which litteraly grab the best price from several options with one calculation only, assuming the CustomerSpecials can't be lower than any Promotions.

If not, you can use Case or Evaluate( ) to determine which is the Min ( ) of the 3.

The same is true and even more powerful in fact with LookupNext ( )

[jscooper]

I KNEW there was a good reason for it .. just couldn't think of any off the top of my head. Thanks.