Get records where json column key is null

Question

I have table users with json column details.

I want to fetch all user records where details[\"email\"] is null or email key doesn\'t exist.

Answer 1

You need to use the ->> operator for that:

select *
from users
where (details->>'email') is not null

Because the -> operator returns 'null'::json (and not sql NULL) if the key is exists but with a json null value.

http://sqlfiddle.com/#!15/76ec4/2

Answer 2

use brackets (). Looks like compiler tries to see it like details->('email' IS NOT NULL). So you can fix it like this:

select *
from users
where (details->'email') is not null

sql fiddle demo

actually, to get records where details["email"] is null or email key doesn't exist, you can use this query:

select *
from users
where (details->>'email') is null

as described in this answer.