Hi list,
I have some trouble matching a value in a JSONB object against multiple potential matches.
Lets say, I have a table with an id, and a metadata JSONB column, which holds data like the following
1 | {"group_id": 1}
2 | {“group_id": 1}
3 | {“group_id": 2}
4 | {“group_id": 3}
I would like to run a query which gives me the result of SELECT id FROM mytable WHERE metadata->>’group_id’ IN (1,2). Now, obviously I could use this query, but I
would like to get away without an explicit index on metadata->>’group_id’, and I was hoping to find something using the JSONB containment operators, with support
of a gist or gin index.
The following seems to work
select * from mytable where (metadata @> '{"group_id":1}')
but only with a single value to match.
I could, of course, also “denormalize” the query a la
select * from mytable where (metadata @> '{"group_id":1}') OR (metadata @> '{"group_id”:2}’)
but this seems to call for long execution times; also, depending on the number of different tag names and values to match this could really explode into quite a
large query.
Stackoverflow suggests the use of ANY
select * from mytable where (tags->'group_id' @> ANY( ARRAY ['1','3']::jsonb[] ) );
https://dba.stackexchange.com/questions/130699/postgresql-json-query-array-against-multiple-values
This seems to work - but doesn’t that require a group_id specific index again?
Anything I overlooked?
Best,
/eno
PS: Please note that I am currently at postgres 9.5. An update, if necessary, would be possible though.
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