Re: pl/pgsql - code review + question

From: "Gary Stainburn" <gary.stainburn@ringways.co.uk>


> Hi all, I've just written my first pl/pgsql function (code included below
for
> you to pull apart).

Looks fine to me. Try it with "SELECT INTO" etc rather than "select into"
and see if you prefer it - I find it makes the variables/fields stand out
better.

> It takes an int4 mid (e.g. 15) and then using a select pulls out the team
> number (e.g. 'NE/012' and a unit number (e.g. 2) and returns the full unit
> number NE/012-02.
>
> I now want to write the reverse function, where I can enter 'NE/012-02'
and
> get back the mid 15.  The bit I'm stuck on is now I split the team part
from
> the member part so that I can build the select statement.

Use the substr() function. Since you are careful to turn member-numbers into
2-digits you shouldn't need anything more complex.

richardh=> select substr('abcdefghijkl',2,3);substr
--------bcd
(1 row)

So, something like

teamnum := substr(idstring,1,6);
membnum := substr(idstring,7,2);

This can get you your team/member which you can query to get your "mid". If
you aren't enforcing uniqueness on (tnumber,mnumber) now might be a good
time to do so.

If the teamnum isn't always a fixed length search for the '-' with strpos()

richardh=> select strpos('abcdefg','e');strpos
--------     5

HTH

- Richard Huxton