How to remove known elements from a JSON[] array in PostgreSQL?

There is currently no = operator defined for the data type json, because there is no well defined method to establish equality of the whole json values. But see below.

You could cast to text and use the = operator then. This is short, but only works if your text representation matches and is unreliable.

Or you can unnest the array and use the ->> operator to .. get JSON object field as text and compare individual fields.

I cannot provide an SQL Fiddle, for some methods for arrays of json are "not yet implemented" in JDBC. Try this at home (pg 9.3+):

Test table

2 rows: first one like in the question, second one with simple values.

CREATE TABLE t (
   t_id int PRIMARY KEY
 , jar  json[]
);

INSERT INTO t VALUES
   (1, '{"{\"value\" : \"03334/254146\", \"typeId\" : \"ea4e7d7e-7b87-4628-ba50-f5\"}"
        ,"{\"value\" : \"03334/254147\", \"typeId\" : \"ea4e7d7e-7b87-4628-ba50-f6\"}"
        ,"{\"value\" : \"03334/254148\", \"typeId\" : \"ea4e7d7e-7b87-4628-ba50-f7\"}"}')

 , (2, '{"{\"value\" : \"a\", \"typeId\" : \"x\"}"
        ,"{\"value\" : \"b\", \"typeId\" : \"y\"}"
        ,"{\"value\" : \"c\", \"typeId\" : \"z\"}"}');

Demos

Demo 1: you could use array_remove() with text representations (unreliable).

SELECT t_id
     , jar, array_length(jar, 1) AS jar_len
     , jar::text[] AS t, array_length(jar::text[], 1) AS t_len
     ,array_remove(jar::text[], '{"value" : "03334/254147", "typeId" : "ea4e7d7e-7b87-4628-ba50-f6"}'::text) AS t_result
     ,array_remove(jar::text[], '{"value" : "03334/254147", "typeId" : "ea4e7d7e-7b87-4628-ba50-f6"}'::text)::json[] AS j_result
FROM t;

Demo 2: unnest the array and test fields of individual elements.

SELECT t_id, array_agg(j) AS j_new
FROM   t
     , unnest(jar) AS j   -- LATERAL JOIN
WHERE  j->>'value' <> '03334/254146'
AND    j->>'typeId' <> 'ea4e7d7e-7b87-4628-ba50-6a5f6e63dbf5'
GROUP  BY 1;

Demo 3: alternative test with row type.

SELECT t_id, array_agg(j) AS j_new
FROM   t
     , unnest(jar) AS j   -- LATERAL JOIN
WHERE  (j->>'value', j->>'typeId') NOT IN (
         ('03334/254146', 'ea4e7d7e-7b87-4628-ba50-6a5f6e63dbf5')
        ,('a', 'x')
       )
GROUP  BY 1;

UPDATE as requested

Finally, this is how you could implement your UPDATE:

UPDATE t
SET    jar = sub.jar
FROM  (
   SELECT t_id, array_agg(j) AS jar
   FROM   (SELECT t_id, jar FROM t WHERE t_id = 2) t  -- reduce to relevant rows
        , unnest(jar) AS j   -- LATERAL JOIN
   WHERE  j->>'value' <> 'a'
   AND    j->>'typeId' <> 'x'
   GROUP  BY 1
   ) sub
WHERE  t.t_id = sub.t_id;

More about the implicit LATERAL JOIN:

• How to turn json array into postgres array?
• Query for element of array in JSON column (SO)

And about unnesting arrays:

• How to preserve the original order of elements in an unnested array?

DB design

To simplify your situation consider an normalized schema: a separate table for the json values (instead of the array column), joined in a n:1 relationship to the main table.

jsonb in Postgres 9.4

You will be interested in the jsonb data type in Postgres 9.4. 'b' is for 'binary'. Among other things, there is an equality operator = for jsonb. Most people will want switch to jsonb.

Depesz blog about jsonb.