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mysqlsqlsql-serverpostgresqlansi-sql

SQL: do we need ANY/SOME and ALL keywords?

I'm using SQL (SQL Server, PostgreSQL) over 10 years and still I'm never used ANY/SOME and ALL keywords in my production code. All situation I've encountered I could get away with IN, MAX, MIN, EXISTS, and I think it's more readable.

For example:

-- = ANY
select * from Users as U where U.ID = ANY(select P.User_ID from Payments as P);

-- IN
select * from Users as U where U.ID IN (select P.User_ID from Payments as P);

Or

-- < ANY
select * from Users as U where U.Salary < ANY(select P.Amount from Payments as P);

-- EXISTS
select * from Users as U where EXISTS (select * from Payments as P where P.Amount > U.Salary);

Using ANY/SOME and ALL:

So the question is: am I missing something? is there some situation where ANY/SOME and ALL shine over other solutions?

Solution

  • I find ANY and ALL to be very useful when you're not just testing equality or inequality. Consider

    'blah' LIKE ANY (ARRAY['%lah', '%fah', '%dah']);

    as used my answer to this question.

    ANY, ALL and their negations can greatly simplify code that'd otherwise require non-trivial subqueries or CTEs, and they're significantly under-used in my view.

    Consider that ANY will work with any operator. It's very handy with LIKE and ~, but will work with tsquery, array membership tests, hstore key tests, and more.

    'a => 1, e => 2'::hstore ? ANY (ARRAY['a', 'b', 'c', 'd'])

    or:

    'a => 1, b => 2'::hstore ? ALL (ARRAY['a', 'b'])

    Without ANY or ALL you'd probably have to express those as a subquery or CTE over a VALUES list with an aggregate to produce a single result. Sure, you can do that if you want, but I'll stick to ANY.

    There's one real caveat here: On older Pg versions, if you're writing ANY( SELECT ... ), you're almost certainly going to be better off in performance terms with EXISTS (SELECT 1 FROM ... WHERE ...). If you're on a version where the optimizer will turn ANY (...) into a join then you don't need to worry. If in doubt, check EXPLAIN output.