Problem s vypoctem v pgsql

[Martin Špirk]

Dne čt 13. ledna 2005 13:12 Ondrej Kolonicny napsal(a):
> Ahoj vsem,
>
> mam tenhle dotaz:
> select to_number(to_char(current_timestamp,
> 'YYYY'),'9999')-(to_number(substring('79999', 1, 2),'99')+1900) ;
> (takhle je funkcni)
> kdyz dam misto retezce '79999' nejakou polozku typu varchar z tabulky
> tak to prestane fungovat.  Poradite nekdo jak to udelat ??
>
> Diky Ondra

U me to funguje v obou pripadech stejne.....

			Martin

********************************************************************************************************************************************

pokus=> select version();
                                                version
--------------------------------------------------------------------------------------------------------
 PostgreSQL 7.4.5 on i686-pc-linux-gnu, compiled by GCC gcc (GCC) 3.4.1 (Mandrakelinux 10.1 3.4.1-4mdk)
(1 řádka)

pokus=> select to_number(to_char(current_timestamp,'YYYY'),'9999')-(to_number(substring('79999', 1, 2),'99')+1900);
 ?column?
----------
       26
(1 řádka)

pokus=> create table abd(a varchar(20));
CREATE TABLE
pokus=> insert into abd values('79999');
INSERT 17739 1
pokus=> select to_number(to_char(current_timestamp, 'YYYY'),'9999')-(to_number(substring(a, 1, 2),'99')+1900) from abd;
 ?column?
----------
       26
(1 řádka)