Postgres jsonb 'NOT contains' operator

23
votes

I'm experimenting with postgres jsonb column types, and so far so good. One common query I'm using is like this: 

select count(*) from jsonbtest WHERE attributes @> '{"City":"Mesa"}';

How do I reverse that? Is there a different operator or is it simply used as 

select count(*) from jsonbtest WHERE NOT attributes @> '{"City":"Mesa"}';
3
postgresqlpostgresql-9.4jsonb
No, there is no dedicated operator for that. What's wrong with NOT? - redneb
@redneb The problem is that NOT simply doesn't work. Using the attributes->>'City' <> 'Mesa' formulation also doesn't work. - eykanal
@eykanal NOT works pretty well. - pozs

3 Answers

17
votes

Two way, you can test any json(b) value

  • the ->> operator extract value as text. But this operation slow, if you will use the value only test
  • the @> operator test any json(b) contain any json(b). This is a quick but you are not tested NOT option.

Simply and quick way: 

NOT (attribute @> '{"City":"Mesa"}'::jsonb)

I've change attribute->>'City' <> 'Mesa' to NOT (attribute @> '{"City":"Mesa"}'::jsonb) and my ~2.000.000 rows query result time changed 45secs to 25secs.

9
votes

This can be achieved with several conditions. It's not elegant but I didn't find another way to do so.

So, first, get every row which simple don't have 'City' attribute and then add 'OR' condition to check for correct field value.

select count(*) from jsonbtest where 
  NOT(attributes ? 'City') 
  OR (attributes ? 'City') is NULL -- this is required if attributes can be null
  OR (attributes->>'City' != 'Mesa'))
-3
votes

You can use the operator <@ this will search where 'City' is not 'Mesa'

select count(*) from jsonbtest WHERE attributes <@ '{"City":"Mesa"}';