Non so se ho capito bene. Comunque....

Primo record :
$query = "SELECT id,data,testo FROM articoli ORDER BY data DESC LIMIT 0,1";

Secondo record :
$query = "SELECT id,data,testo FROM articoli ORDER BY data DESC LIMIT 1,1";

Terzo record :
$query = "SELECT id,data,testo FROM articoli ORDER BY data DESC LIMIT 2,1";

etc...