Re: Map file-glob-style patterns to SQL "LIKE" expressions, with escaping

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Re^2: Map file-glob-style patterns to SQL "LIKE" expressions, with escaping by graff (Chancellor) on Apr 01, 2005 at 03:21 UTC
If the original file-glob string is something like: `what\?_not\.%` [download] a file-glob sees a backslash escape before the "?" and "" (to match a literal question mark and asterisk), and treats "_" and "%" as normal (literal) characters. For conversion to an sql "like" pattern, the "\" must be removed from in front of "?" and "*" (because these characters don't need to be escaped now) and must be added in front of each "_" and "%" (to keep them literal, as they were in the file-glob).	[reply] [d/l]
Re^3: Map file-glob-style patterns to SQL "LIKE" expressions, with escaping by merlyn (Sage) on Apr 01, 2005 at 03:28 UTC
Precisely. This exact mapping took me enough time to work out that I thought I'd share it. You got it perfectly. -- Randal L. Schwartz, Perl hacker Be sure to read my standard disclaimer if this is a reply.	[reply]
Re^2: Map file-glob-style patterns to SQL "LIKE" expressions, with escaping by merlyn (Sage) on Apr 01, 2005 at 03:11 UTC
It maps * to % and ? to _, so I can write "??a*", and get any three-or-more character value where the 3rd character is "a". It's mapping to SQL. I'm not putting anything in there that isn't understood in standard SQL92. -- Randal L. Schwartz, Perl hacker Be sure to read my standard disclaimer if this is a reply.	[reply]