Re: BUG #5469: regexp_matches() has poor behaviour and more poor documentation

On 2010-05-26, Daniele Varrazzo <daniele.varrazzo@gmail.com> wrote:

> [regexp_matches:] Return all groups of captured substrings resulting
> from matching a POSIX regular expression against the string. Warning:
> in case of no match, tested record is dropped. See Section 9.7.3 for
> more information.

possibly like this instead.

 [regexp_matches:] Return all groups of captured substrings resulting
 from matching a POSIX regular expression against the string. Note:
 one row is returned for each match, no matches results in no rows,
 several matches results in several rows.



> In section 9.7.3, after "If there is no match to the pattern, the
> function returns no rows." I would add "This means that if the
> function is used in a SELECT, records where the string don't match the
> pattern are discarded from the dataset. If such records are required,
> use regexp_match() instead".

or use an outer join to a subquery if you want to see all the results.