SELECT [ ALL | DISTINCT [ ON ( expression [, ...] ) ] ]
expression [ AS name ] [, ...]
[ INTO [ TEMPORARY | TEMP ] [ TABLE ] new_table ]
[ FROM table [ alias ] [, ...] ]
[ WHERE condition ]
[ GROUP BY column [, ...] ]
[ HAVING condition [, ...] ]
[ { UNION [ ALL ] | INTERSECT | EXCEPT } select ]
[ ORDER BY column [ ASC | DESC | USING operator ] [, ...] ]
[ FOR UPDATE [ OF class_name [, ...] ] ]
LIMIT { count | ALL } [ { OFFSET | , } start ]
DISTINCT elimina registros duplicados del resultado. ALL (predeterminado) devolverá todos los registros, que cumplan con la consulta, incluyendo los duplicados.
La cláusula GROUP BY permite al usuario dividir una tabla conceptualmente en grupos.
un saludo.
