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Re: How to allow null as an option when using regexp_matches? - Mailing list pgsql-general

From Shaozhong SHI
Subject Re: How to allow null as an option when using regexp_matches?
Date
Msg-id CA+i5Jwb0A=_Uh+CbAm9qeXC5otc1fWWEUsPqA8Ci4cng3qTgdw@mail.gmail.com
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In response to Re: How to allow null as an option when using regexp_matches?  (Karsten Hilbert <Karsten.Hilbert@gmx.net>)
Responses Re: How to allow null as an option when using regexp_matches?  (Vincent Veyron <vv.lists@wanadoo.fr>)
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Hi, Karsten,

That sounds interesting.

Any good example?

Regards,  David

On Wed, 8 Dec 2021 at 12:10, Karsten Hilbert <Karsten.Hilbert@gmx.net> wrote:
Am Wed, Dec 08, 2021 at 12:07:13PM +0000 schrieb Shaozhong SHI:

> We can do this:
> select count(*) from regexp_matches('Great London', 'Great
> London|Information Centre|Department for Transport', 'g');
>
> Is it possible to allow null as an option?  something like this
> select count(*) from regexp_matches('Great London', 'null|Great
> London|Information Centre|Department for Transport', 'g');

You seem to want to apply coalesce() judiciously.

Best,
Karsten
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