jak obelstit razeni v PSQL ?

[Radek Kanovsky]

On Fri, Sep 14, 2001 at 02:40:44PM +0200, Karel Zak wrote:

> On Fri, Sep 14, 2001 at 02:01:34PM +0200, Zdenek Pizl wrote:
> > >
> > > K tomuto - nemyslel jsem script na zobrazovani ale script
> > > na zmenu, tzn. nacist, upravit a ulozit ...
> > 
> > aha, ja to asi obelstim pomoci CASE WHEN END podminky, ale 
> > je to prasarna ...
> 
> SELECT	CASE WHEN name LIKE 'Praha %' 
> 	THEN 
> 		substring(name from 0 for 7) || 
> 		trim( both '0' from substring(name from 7)) 
> 	ELSE 
> 		name 
> 	END 
> FROM	mesto
> ORDER BY name;

V postgresu by to mohlo jit pres nejaky mazany operator,
ktery bude pravdepodobne potreba vytvorit.

CREATE OPERATOR <cityop> .......
SELECT name FROM mesto ORDER BY name USING <cityop>;

Nikdy jsem to nezkousel, ale dokumentace vypada dobre.
S timto operatorem by to slo i rovnou oindexovat
pro rychlejsi razeni:

CREATE INDEX mesto_cityop ON mesto (mesto <cityop>);

Zdravi,

Radek Kaňovský