Field entry of data can be problematic - touch screen, sunlight, incomplete data, typos. In many cases it may consist of entering a serial number from an equipment tag, and equipment mfg, type, size, etc.. Ideally, one would enter a serial number, and the other fields would autofill, allowing immediate verification that the tag number was entered correctly, avoiding the need to type the rest of the information, and ensuring consistent values. In a database, a trigger can be set to do this on departure from the entry field; ArcGIS manages database operations, so this method is not available. It can be scripted as a scheduled task, using a "lookup table" and the serial number. "Lookup" is quoted - I am using it in the general software sense - a non-changing prepopulated dictionary - and not the specific ESRI raster usage. This results in two problems - since a trigger is not available, field personnel don't get the immediate autofill that would allow them to verify the entry. The second problem is that the closest approximation to this technique is using a related table to store the "lookup" data. This is problematic, as deletion of a serial number (primary key) will result in a null key or record deletion in the related table.
I would like to either have access to database triggers to run a script on changing a particular field, or the ability to have a "related" table that does not delete the key values or records - essentially a write-protected related table.