Extend table vs reference field?

oko
Kilo Explorer

‎08-17-2017 01:01 PM

Hi - just seeking a bit of nuance on this - If I create a new table (A), and I choose to extend an existing one (Z) as I create the new table A, I automatically start with all the columns in the existing one, until I start adding new columns in A, correct?     So why is that different than just creating Reference fields as I go in A instead?

Is it simply more convenient/efficient if I know in advance I need most/all of the fields from Z in my new A table to just extend, rather than add them in one by one via Reference fields;   or is one more performant than the other, or?

Just want to understand the base difference here - as a test, I created a test table that extended "Alias" and I get all those fields in my new test table of course, BUT, they aren't Reference fields, they are whatever field type they were in Alias?     I'm probably just missing something obvious here, but...?

kevin

0 Helpfuls
  • 1,770 Views
1 REPLY 1

Chay2
Mega Guru

‎08-17-2017 01:11 PM

Hi Kevin,


If you extend an existing table, you inherit the built-in functionality of the base table. if you want to use a reference field it is a foreign key from a different table.


I think this link will help you   https://developer.servicenow.com/app.do#!/training/article/app_store_learn_dev_platform_intro_istanb...


0 Helpfuls