Re: Passing function parameters to regexp_replace

Leif Biberg Kristensen <leif(at)solumslekt(dot)org> wrote:

>> UPDATE sources SET source_text = regexp_replace(source_text,
>> E'n="(.*?)$1(.*?)"', E'n="\\1$2\\2"', 'g') where source_text like
>> '%n="%$2%">%';

> Sorry, I pasted a literal replacement, and substituted the parameters by hand.
> The expression should of course be

> UPDATE sources SET source_text = regexp_replace(source_text,
> E'n="(.*?)$1(.*?)"', E'n="\\1$2\\2"', 'g') where source_text like
> '%n="%$1%">%'

Try:

> UPDATE sources SET source_text = regexp_replace(source_text,
> CONCAT(E'n="(.*?)', $1, E'(.*?)"'), CONCAT(E'n="\\1', $2, '\\2"', 'g') where source_text like
> CONCAT('%n="%', $1, '%">%')

If $1 and $2 (can) include meta characters, you have to es-
cape them properly.

Please consider that regexp_replace() uses POSIX Regular
Expressions while LIKE uses a different syntax. If possible,
I would replace the LIKE expression with its "~" equivalent
so chances of confusion are minimized.

Tim