a = ANY(b_array)
is equivalent to a
IN
(elements_of_b_array)
1.
Therefore you can use the in_()
method.
I can't remember ever having used a = ALL(b_array)
in all my years with PostgreSQL. Have you?
If you are dealing with an array column and want to test whether it contains a given element (or all elements of a given array) in that column, then you can utilize PostgreSQL array operators @>
(contains
) or more appropriately the inverse sibling <@
(is contained by
).
Array operators carry the advantage that they can be supported with a GIN index on the array column (unlike the ANY
construct).
Your SQL statement:
SELECT * FROM my_table WHERE 10000 = ANY (array_field);
is (almost)1 equivalent to
SELECT * FROM my_table WHERE 10000 <@ array_field;
I am no expert with SQLAlchemy, but according to the tutorial in the SQLAlchemy manual, you can use any operator:
If you have come across an operator which really isn’t available, you
can always use the op()
method; this generates whatever
operator you need:
>>> print users.c.name.op('tiddlywinks')('foo') users.name tiddlywinks :name_1
Bold emphasis mine. Your statement could look like this in SQLA:
s = select([my_table], array_field.op('@>')('ARRAY[10000]'))
Or with alternative input syntax for PostgreSQL array values:
s = select([my_table], array_field.op('@>') (cast('{10000}', int[])))
1 There is a subtle difference with NULL handling:
SELECT '{NULL}'::int[] <@ ... -- that's an array with a single NULL element
always yields FALSE
.
SELECT NULL IN (...)
SELECT NULL = ANY (...)
SELECT NULL::int[] <@ ...
always yield NULL
.
If you are not going to query for NULL
values, you can ignore this.