Re: using replace function

"David G. Johnston" <david.g.johnston@gmail.com> writes:
> On Thursday, November 28, 2019, Rob Sargent <robjsargent@gmail.com> wrote:
>> I want to replace a string (not a substring) in a field but making sure
>> that the string in the full field.

> I’d probably do something like:
> Select case when a.col = ‘value’ then ‘new value’ else a.col end from a;

Yeah, this.  You could wrap it up in a SQL function if you want the
same level of notational convenience as replace().

Another possibility is regexp_replace with an anchored pattern, but
that would potentially require escaping regexp metacharacters in the
pattern, so the PITA factor is high.  And I doubt it'd be faster than
the CASE solution.

            regards, tom lane