[sql] How do I query using fields inside the new PostgreSQL JSON datatype?

I am looking for some docs and/or examples for the new JSON functions in PostgreSQL 9.2.

Specifically, given a series of JSON records:

[
  {name: "Toby", occupation: "Software Engineer"},
  {name: "Zaphod", occupation: "Galactic President"}
]

How would I write the SQL to find a record by name?

In vanilla SQL:

SELECT * from json_data WHERE "name" = "Toby"

The official dev manual is quite sparse:

• http://www.postgresql.org/docs/devel/static/datatype-json.html
• http://www.postgresql.org/docs/devel/static/functions-json.html

Update I

I've put together a gist detailing what is currently possible with PostgreSQL 9.2. Using some custom functions, it is possible to do things like:

SELECT id, json_string(data,'name') FROM things
WHERE json_string(data,'name') LIKE 'G%';

Update II

I've now moved my JSON functions into their own project:

PostSQL - a set of functions for transforming PostgreSQL and PL/v8 into a totally awesome JSON document store

With postgres 9.3 use -> for object access. 4 example

seed.rb

se = SmartElement.new
se.data = 
{
    params:
    [
        {
            type: 1,
            code: 1,
            value: 2012,
            description: 'year of producction'
        },
        {
            type: 1,
            code: 2,
            value: 30,
            description: 'length'
        }
    ]
}

se.save

rails c

SELECT data->'params'->0 as data FROM smart_elements;

returns

                                 data
----------------------------------------------------------------------
 {"type":1,"code":1,"value":2012,"description":"year of producction"}
(1 row)

You can continue nesting

SELECT data->'params'->0->'type' as data FROM smart_elements;

return

 data
------
 1
(1 row)

With Postgres 9.3+, just use the -> operator. For example,

SELECT data->'images'->'thumbnail'->'url' AS thumb FROM instagram;

see http://clarkdave.net/2013/06/what-can-you-do-with-postgresql-and-json/ for some nice examples and a tutorial.