ANY
(or its synonym SOME
) is a syntax sugar for EXISTS
with a simple correlation:
SELECT *
FROM mytable
WHERE x <= ANY
(
SELECT y
FROM othertable
)
is the same as:
SELECT *
FROM mytable m
WHERE EXISTS
(
SELECT NULL
FROM othertable o
WHERE m.x <= o.y
)
With the equality condition on a not-nullable field, it becomes similar to IN
.
All major databases, including SQL Server
, MySQL
and PostgreSQL
, support this keyword.