How do I modify fields inside the new PostgreSQL JSON datatype?

Question

With postgresql 9.3 I can SELECT specific fields of a JSON data type, but how do you modify them using UPDATE? I can\'t find any examples of this in the postgresql documenta

Answer 1

This worked for me, when trying to update a string type field.

UPDATE table_name 
SET body = jsonb_set(body, '{some_key}', to_json('value'::text)::jsonb);

Hope it helps someone else out!

Assuming the table table_name has a jsonb column named body and you want to change body.some_key = 'value'

Answer 2

With Postgresql 9.5 it can be done by following-

UPDATE test
SET data = data - 'a' || '{"a":5}'
WHERE data->>'b' = '2';

OR

UPDATE test
SET data = jsonb_set(data, '{a}', '5'::jsonb);

---

Somebody asked how to update many fields in jsonb value at once. Suppose we create a table:

CREATE TABLE testjsonb ( id SERIAL PRIMARY KEY, object JSONB );

Then we INSERT a experimental row:

INSERT INTO testjsonb
VALUES (DEFAULT, '{"a":"one", "b":"two", "c":{"c1":"see1","c2":"see2","c3":"see3"}}');

Then we UPDATE the row:

UPDATE testjsonb SET object = object - 'b' || '{"a":1,"d":4}';

Which does the following:

1. Updates the a field
2. Removes the b field
3. Add the d field

Selecting the data:

SELECT jsonb_pretty(object) FROM testjsonb;

Will result in:

      jsonb_pretty
-------------------------
 {                      +
     "a": 1,            +
     "c": {             +
         "c1": "see1",  +
         "c2": "see2",  +
         "c3": "see3",  +
     },                 +
     "d": 4             +
 }
(1 row)

To update field inside, Dont use the concat operator ||. Use jsonb_set instead. Which is not simple:

UPDATE testjsonb SET object =
jsonb_set(jsonb_set(object, '{c,c1}','"seeme"'),'{c,c2}','"seehim"');

Using the concat operator for {c,c1} for example:

UPDATE testjsonb SET object = object || '{"c":{"c1":"seedoctor"}}';

Will remove {c,c2} and {c,c3}.

For more power, seek power at postgresql json functions documentation. One might be interested in the #- operator, jsonb_set function and also jsonb_insert function.

Answer 3

UPDATE table_name SET attrs = jsonb_set(cast(attrs as jsonb), '{key}', '"new_value"', true) WHERE id = 'some_id';

This what worked for me, attrs is a json type field. first cast to jsonb then update.

or

UPDATE table_name SET attrs = jsonb_set(cast(attrs as jsonb), '{key}', '"new_value"', true) WHERE attrs->>key = 'old_value';