How to make a IN query with hstore? - sql

Question

I have a field (content) in a table containing keys and values (hstore) like this :
content: {"price"=>"15.2", "quantity"=>"3", "product_id"=>"27", "category_id"=>"2", "manufacturer_id"=>"D"}
I can easily select product having ONE category_id with :
SELECT * FROM table WHERE "content #> 'category_id=>27'"
I want to select all lines having (for example) category_id IN a list of value.
In classic SQL it would be something like this :
SELECT * FROM TABLE WHERE category_id IN (27, 28, 29, ....)
Thanks you in advance

Answer 1

De-reference the key and test it with IN as normal.
CREATE TABLE hstoredemo(content hstore not null);
INSERT INTO hstoredemo(content) VALUES
('"price"=>"15.2", "quantity"=>"3", "product_id"=>"27", "category_id"=>"2", "manufacturer_id"=>"D"');
then one of these. The first is cleaner, as it casts the extracted value to integer rather than doing string compares on numbers.
SELECT *
FROM hstoredemo
WHERE (content -> 'category_id')::integer IN (2, 27, 28, 29);
SELECT *
FROM hstoredemo
WHERE content -> 'category_id' IN ('2', '27', '28', '29');
If you had to test more complex hstore contains operations, say with multiple keys, you could use #> ANY, e.g.
SELECT *
FROM hstoredemo
WHERE
content #> ANY(
ARRAY[
'"category_id"=>"27","product_id"=>"27"',
'"category_id"=>"2","product_id"=>"27"'
]::hstore[]
);
but it's not pretty, and it'll be a lot slower, so don't do this unless you have to.

Answer 2

category_ids = ["27", "28", "29"]
Tablename.where("category_id IN(?)", category_ids)