COUNT DISTINCT
Sintassi
COUNT(DISTINCT espr,[espr...])
Spiegazione
Restituisce il numero di valori non-NULL differenti.
COUNT(DISTINCT) restituisce 0 se non vi sono righe.
Esempi
mysql> SELECT COUNT(DISTINCT voti) FROM studenti;
Commenti
Sto caricando i commenti......
Content reproduced on this site is the property of its respective owners,
and this content is not reviewed in advance by MariaDB. The views, information and opinions
expressed by this content do not necessarily represent those of MariaDB or any other party.
