Postgresql – Modify all array entries in all records of a table at once

I think yes. Haven't tried with actual INSERTs or UPDATEs yet, but this function works:

CREATE TABLE a (id integer);

CREATE OR REPLACE FUNCTION arraytest2(rec a[]) RETURNS SETOF integer AS
$body$
SELECT b.*
FROM unnest($1) b;
$body$
LANGUAGE sql;

This way you can write your INSERT statement as

INSERT INTO tbl_weightment 
SELECT (r).*
FROM unnest(rec) r;

And UPDATE as

UPDATE tbl_weightment 
SET 
    vname = r.vname,
    iquality = r.iquality,
    vhooks = r.vhooks,
    tstamp = r.tstamp
    vtare = r.vtare,
    vgross = r.vgross 
FROM unnest(rec) r
WHERE id=rec.id;

jsonb in Postgres 9.4 or later

Consider the jsonb data type in Postgres 9.4 or later. The 'b' at the end stands for 'binary'. Among other things, there is an equality operator (=) for jsonb. Most people will want to switch.

Depesz blog about jsonb.

json

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

You could cast to text and then use the = operator. This is short, but only works if your text representation happens to match. Inherently unreliable, except for corner cases. See:

• How to query a json column for empty objects?

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

Test table

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

CREATE TABLE tbl (
   tbl_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

You could use array_remove() with text representations (unreliable).

SELECT tbl_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   tbl;

Unnest the array and test fields of individual elements.

SELECT tbl_id, array_agg(j) AS j_new
FROM   tbl, unnest(jar) AS j   -- LATERAL JOIN
WHERE  j->>'value' <> '03334/254146'
AND    j->>'typeId' <> 'ea4e7d7e-7b87-4628-ba50-6a5f6e63dbf5'
GROUP  BY 1;

Alternative test with row type.

SELECT tbl_id, array_agg(j) AS j_new
FROM   tbl, 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 tbl t
SET    jar = j.jar
FROM   tbl t1
CROSS  JOIN LATERAL (
   SELECT ARRAY(
      SELECT j
      FROM   unnest(t1.jar) AS j  -- LATERAL JOIN
      WHERE  j->>'value'  <> 'a'
      AND    j->>'typeId' <> 'x'
      ) AS jar
   ) j
WHERE  t1.tbl_id = 2              -- only relevant rows
AND    t1.tbl_id = t.tbl_id;

db<>fiddle here

About the implicit LATERAL JOIN:

• How to turn JSON array into Postgres array?
• Query for element of array in JSON column

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.