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

这对我有用，attrs是一个json类型的字段。首先转换为jsonb，然后更新。

or

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

对于那些使用mybatis的人，这里有一个更新语句示例:

<update id="saveAnswer">
    update quiz_execution set answer_data = jsonb_set(answer_data, concat('{', #{qid}, '}')::text[], #{value}::jsonb), updated_at = #{updatedAt}
    where id = #{id}
</update>

参数:

Qid, field的键。 是一个有效的json字符串，对于字段值， 通过jackson将对象转换为json字符串，

在@pozs回答的基础上，这里有两个可能对一些人有用的PostgreSQL函数。(需要PostgreSQL 9.3+)

按键删除:按键从JSON结构中删除一个值。

CREATE OR REPLACE FUNCTION "json_object_del_key"(
  "json"          json,
  "key_to_del"    TEXT
)
  RETURNS json
  LANGUAGE sql
  IMMUTABLE
  STRICT
AS $function$
SELECT CASE
  WHEN ("json" -> "key_to_del") IS NULL THEN "json"
  ELSE (SELECT concat('{', string_agg(to_json("key") || ':' || "value", ','), '}')
          FROM (SELECT *
                  FROM json_each("json")
                 WHERE "key" <> "key_to_del"
               ) AS "fields")::json
END
$function$;

按键递归删除:按键路径从JSON结构中删除一个值。(需要@pozs的json_object_set_key函数)

CREATE OR REPLACE FUNCTION "json_object_del_path"(
  "json"          json,
  "key_path"      TEXT[]
)
  RETURNS json
  LANGUAGE sql
  IMMUTABLE
  STRICT
AS $function$
SELECT CASE
  WHEN ("json" -> "key_path"[l] ) IS NULL THEN "json"
  ELSE
     CASE COALESCE(array_length("key_path", 1), 0)
         WHEN 0 THEN "json"
         WHEN 1 THEN "json_object_del_key"("json", "key_path"[l])
         ELSE "json_object_set_key"(
           "json",
           "key_path"[l],
           "json_object_del_path"(
             COALESCE(NULLIF(("json" -> "key_path"[l])::text, 'null'), '{}')::json,
             "key_path"[l+1:u]
           )
         )
       END
    END
  FROM array_lower("key_path", 1) l,
       array_upper("key_path", 1) u
$function$;

使用例子:

s1=# SELECT json_object_del_key ('{"hello":[7,3,1],"foo":{"mofu":"fuwa", "moe":"kyun"}}',
                                 'foo'),
            json_object_del_path('{"hello":[7,3,1],"foo":{"mofu":"fuwa", "moe":"kyun"}}',
                                 '{"foo","moe"}');

 json_object_del_key |          json_object_del_path
---------------------+-----------------------------------------
 {"hello":[7,3,1]}   | {"hello":[7,3,1],"foo":{"mofu":"fuwa"}}

select * from pg_settings where name = 'deadlock_timeout';
begin;
create temp table a2(data jsonb);
insert into a2 values('{
    "key0": {
        "key01": "2018-05-06T12:36:11.916761+00:00",
        "key02": "DEFAULT_WEB_CONFIGURATION",
    "key1": {
        "key11": "Data System",
        "key12": "<p>Health,<p>my address<p>USA",
        "key13": "*Please refer to main screen labeling"
    }
}}'::jsonb);
commit;

嵌套的jsonb结构更新。可应用于删除。

update a2 set data =
    data::jsonb #-  '{key0, key1, key13}'
        || '{"key13":"screen labeling"}'::jsonb
returning *;

你也可以像这样在jsonb中原子地增加键:

UPDATE users SET counters = counters || CONCAT('{"bar":', COALESCE(counters->>'bar','0')::int + 1, '}')::jsonb WHERE id = 1;

SELECT * FROM users;

 id |    counters
----+------------
  1 | {"bar": 1}

>假设起始值为0。

更详细的解释，请看我的回答:https://stackoverflow.com/a/39076637

在PostgreSQL 9.4中，我们实现了以下python函数。它也可以用于PostgreSQL 9.3。

create language plpython2u;

create or replace function json_set(jdata jsonb, jpaths jsonb, jvalue jsonb) returns jsonb as $$
import json

a = json.loads(jdata)
b = json.loads(jpaths)

if a.__class__.__name__ != 'dict' and a.__class__.__name__ != 'list':
  raise plpy.Error("The json data must be an object or a string.")

if b.__class__.__name__ != 'list':
   raise plpy.Error("The json path must be an array of paths to traverse.")

c = a
for i in range(0, len(b)):
  p = b[i]
  plpy.notice('p == ' + str(p))

  if i == len(b) - 1:
    c[p] = json.loads(jvalue)

  else:
    if p.__class__.__name__ == 'unicode':
      plpy.notice("Traversing '" + p + "'")
      if c.__class__.__name__ != 'dict':
        raise plpy.Error("  The value here is not a dictionary.")
      else:
        c = c[p]

    if p.__class__.__name__ == 'int':
      plpy.notice("Traversing " + str(p))
      if c.__class__.__name__ != 'list':
        raise plpy.Error("  The value here is not a list.")
      else:
        c = c[p]

    if c is None:
      break    

return json.dumps(a)
$$ language plpython2u ;

使用示例:

create table jsonb_table (jsonb_column jsonb);
insert into jsonb_table values
('{"cars":["Jaguar", {"type":"Unknown","partsList":[12, 34, 56]}, "Atom"]}');

select jsonb_column->'cars'->1->'partsList'->2, jsonb_column from jsonb_table;

update jsonb_table
set jsonb_column = json_set(jsonb_column, '["cars",1,"partsList",2]', '99');

select jsonb_column->'cars'->1->'partsList'->2, jsonb_column from jsonb_table;

Note that for a previous employer, I have written a set of C functions for manipulating JSON data as text (not as a json or jsonb type) for PostgreSQL 7, 8 and 9. For example, extracting data with json_path('{"obj":[12, 34, {"num":-45.67}]}', '$.obj[2]['num']'), setting data with json_path_set('{"obj":[12, 34, {"num":-45.67}]}', '$.obj[2]['num']', '99.87') and so on. It took about 3 days work, so if you need it to run on legacy systems and have the time to spare, it may be worth the effort. I imagine the C version is much faster than the python version.