Prova con
SELECT id_cliente, COUNT(id_prodotto) AS num_prodotti FROM
tuatabella GROUP BY id_cliente HAVING num_prodotti = 1
Prova con
SELECT id_cliente, COUNT(id_prodotto) AS num_prodotti FROM
tuatabella GROUP BY id_cliente HAVING num_prodotti = 1
In a world without walls and fences - who needs windows and gates ?