Re: How best to work around the issue - regex string cannot contain brackets

It appears that the following regex work differently.

Why \d and [\d] are different?

[A-PR-UWYZ]\d{1,2} and [A-PR-UWYZ][\d]{1,2}

Regards,

David

On Thu, 3 Feb 2022 at 17:04, David G. Johnston <david(dot)g(dot)johnston(at)gmail(dot)com>
wrote:

> On Thu, Feb 3, 2022 at 9:58 AM Christophe Pettus <xof(at)thebuild(dot)com> wrote:
>
>>
>>
>> > On Feb 3, 2022, at 08:53, Shaozhong SHI <shishaozhong(at)gmail(dot)com> wrote:
>> >
>> > One would consider the following would work, but it did not because the
>> brackets.
>> > select regexp_matches('Department for Transport (Parking)', 'Department
>> for Transport (Parking)', 'g')
>> >
>> > Can anyone enlighten me?
>>
>
> Have you tried reading a book or some tutorials on RegExes? I'll admit
> our documentation is probably not the best resource out there to actually
> learn the language.
>
>
>> You escape the ()s with a backslash:
>>
>
> More generally this behavior this documented as "\k"
>
>
> https://www.postgresql.org/docs/current/functions-matching.html#FUNCTIONS-POSIX-REGEXP
>
> David J.
>
>