Re: update field using substrings of another field

Doug McNaught <doug(at)mcnaught(dot)org> writes:
> "Dave [Hawk-Systems]" <dave(at)hawk-systems(dot)com> writes:
>> Have a table with fnumber and number, both text
>> fnumber is a phone number, format "8005551212"
>> number needs to be the same number but in the format "(800) 555-1212"

> You could do it fairly easily with a trigger.

Or consider plan B: why bother to actually store "number" at all,
if it is trivially computable from "fnumber"?

You could make a view that includes "number" as a derived column,
if you have apps that insist on seeing it as an ordinary-looking
column in the select result.

regards, tom lane