How to convert PostgreSQL 9.4's jsonb type to float

Question

I\'m trying the following query:

SELECT (json_data->\'position\'->\'lat\') + 1.0 AS lat FROM updates LIMIT 5;

(The +1.0 is just there

Answer 1

Adding a clarification because this comes up as the top hit for a 'JSONB float conversion' search - note that you need to wrap the JSON conversion in brackets, and then apply the '::' casting.

As mentioned above, the correct method is:

(json_data #>> '{field}')::float

If instead you try this it will fail:

json_data #>> '{field}'::float

This was the mistake I was making in my code and it took me a while to see it - easy fix once I noticed.