if exists...does it exists for insert statments?

["Pau Marc Munoz Torres" <paumarc@xxxxxxxxx>]

could i use a sentence similar to the mysql sentence

insert if not exist into SP values ('cesp','sp');

in postgresql?

pau


-- 
Pau Marc Muñoz Torres

Laboratori de Biologia Computacional   
Institut de  Biotecnologia   i Biomedicina Vicent Villar                                    
Universitat Autonoma de Barcelona
E-08193 Bellaterra (Barcelona)
              
telèfon: 93 5812807
Email : 
paumarc.munoz@xxxxxxxxxxxxxx