Re: Odd behavior with LIKE? - Mailing list pgsql-general

From GH
Subject Re: Odd behavior with LIKE?
Date
Msg-id 20010611142302.A4867@over-yonder.net
Whole thread Raw
In response to Odd behavior with LIKE?  ("Tim Barnard" <tbarnard@povn.com>)
List pgsql-general
On Mon, Jun 11, 2001 at 11:00:36AM -0700, some SMTP stream spewed forth:
> I've noticed that if I don't preceed an underscore character ( _ )
> with a double backslash ( \\ ), then a select using LIKE
> ignores the underscore. For example, I have a couple of indexes
> that end with "_ts" and a few tables that end in "ts":

Quote /usrs-lounge/docs/7.1/user/functions-matching.html#FUNCTIONS-LIKE
...
An underscore (_) in pattern stands for (matches) any single character; a
percent sign (%) matches any string of zero or more characters.
...
'abc' LIKE '_b_'    true

> select relname from pg_class where relname not like 'pg\\_%' and relname not like '%\\_pkey' and relname not like
'\\_ts';
>
> Question is: Why must the underscore character
> be prefixed with a double-backslash?

It must be escaped because it a special pattern-matching character.


gh

> Tim
>

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