in reply to regular expressions: from general to Perl to SQL

SQL only knows placeholders equivalent to .* and .?. Anything more advanced is not doable in standards compliant SQL; though your specific database's dialect may support such expressions. Check the fine manual.

Update: that's ., not .?. Oops.

Makeshifts last the longest.

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Re: Re: regular expressions: from general to Perl to SQL
by princepawn (Parson) on Aug 14, 2003 at 21:20 UTC
    Yeah, anything more advanced is not necessary for the regular expression task at hand... portability to Perl and SQL is more important than doing nose-bleed things with Perl...

    I may be forced to whip something up... or maybe japhy has something unreleased.

    Carter's compass: I know I'm on the right track when by deleting something, I'm adding functionality

[reply]
      But you do have \b and \s* in your source.. those can't be emulated in SQL. In any case, since the SQL wildcards are % and _ (corresponding to .* and ., respectively), they're easy to replace to produce Perl regex syntax. So I'd store the profanity words with SQL wildcards in the definition and then 
      my %rx_wild_for = ( '%' => '.*', '_' => '.' );
$profane = s/[%_]/$rx_wild_for{$1}/g;

      [download]
      or something.

      Makeshifts last the longest.

[reply]
[d/l]

      The simplest solution that springs to my mind is to store the SQL-compatible patterns and do a simple search-and-replace to translate them into Perl regex as needed. If there are truly only 2 different matching chars (equiv to .* and .?), this is a fairly trivial task.

[reply]

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