Re: How to retrieve N lines of a text field.

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От Tom Lane
Тема Re: How to retrieve N lines of a text field.
Дата
Msg-id 22882.1075391421@sss.pgh.pa.us
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Ответ на How to retrieve N lines of a text field.  ("Chris Travers" <chris@travelamericas.com>)
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"Chris Travers" <chris@travelamericas.com> writes:
> However, this always selects every line but the final one (because %\n seems
> to be interpreted to be the largest possible string, while I want it to be
> the smallest possible string).

I don't think you can solve this in SQL99 regular expressions, but
if you use the POSIX-style regex operators, you can write something
like "[^\n]*\n" to match exactly one line.  There are other features
that might help too, such as the counted-match operator "{n}".
Read the man page.

BTW, I bought a copy of the O'Reilly book "Mastering Regular
Expressions" a couple years ago, and it is worth every penny
if you do much of anything with regexes.
        regards, tom lane


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