From Dwayne Wright PMP, PMI-ACP, CSM
Certified FileMaker Developer
The Lookup is when you have a field in the parent table occurrence that will copy the information from a child table occurrence. The copy information is triggered when the data within the parent match field in a relationship is refreshed.
A lookup can take place in at least five different situations. When data is first entered into a parent field of a relationship, the lookup is executed for that record. When data is edited in a parent field of a relationship, the lookup is executed for that record. When the replace command is executed within a parent key field of a relationship, the lookup is executed for all the records in the found set. When data is imported in from another file into a parent field of a relationship, the lookup is executed for that record ( note ... this can be turned off via one of the import dialog boxes). There is also a relookup command under the File menu and as a ScriptMaker step. When the relookup command is executed for a parent key field of a relationship, the lookup is executed for that record.
LOOKING AT A DIFFERENT WAY
Related data is also triggered or refreshed when data within the parent match field in a relationship is updated. Related data resides in the other table occurrence but can also be used in calculations, finds, sorts and even value lists.
Any time you can introduce the calculation engine in a place you wouldn’t expect it, your design options extend radically. The auto enter via a calculated result is no exception. For traditional lookup duties, consider using an auto enter via calculation option. You can simply set the calculation equal to the related value and they serve the same purpose. However, using an auto enter calculated value gives you much more flexibility in regards of what you want to do with the lookup operation in the future.
First off, you can branch when the auto enter triggers and you cannot do that with a traditional lookup. Instead of just a key field being modified, you can add other criteria by adding a simple AND operator.
Second, you can adjust was is returned. Instead of bring over the contents of just one field, you can bring over concatenated information from multiple fields, literal text, get function data or a combination thereof.
So I think the auto enter via calculation does everything the lookup could do and has the potential of much more. If you have any feedback to give me on this, by all means please do so. Would love to hear your impressions on this.
More info about the author and FileMaker in general, contact me at email@example.com.
© 2008 - Dwayne Wright - dwaynewright.com
The material on this document is offered AS IS. There is NO REPRESENTATION OR WARRANTY, expressed or implied, nor does any other contributor to this document. WARRANTIES OF MERCHANT ABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE EXPRESSLY DISCLAIMED. Consequential and incidental damages are expressly excluded. FileMaker Pro is the registered trademark of FileMaker Inc.