如果你想添加新的字段，你可以尝试:

typeorm代码

let keyName:string = '{key2}'
let valueName:string = '"new_value"'

emailLog: () => "jsonb_set(cast(email_log as jsonb), '" + keyNAme + "','" + valueName + "'," + "true" + ")"

遗憾的是，我没有在文档中找到任何东西，但您可以使用一些变通方法，例如您可以编写一些扩展函数。

例如，在Python中:

CREATE or REPLACE FUNCTION json_update(data json, key text, value json)
returns json
as $$
from json import loads, dumps
if key is None: return data
js = loads(data)
js[key] = value
return dumps(js)
$$ language plpython3u

然后

update test set data=json_update(data, 'a', to_json(5)) where data->>'b' = '2';

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"}}

下面的plpython代码片段可能会派上用场。

CREATE EXTENSION IF NOT EXISTS plpythonu;
CREATE LANGUAGE plpythonu;

CREATE OR REPLACE FUNCTION json_update(data json, key text, value text)
 RETURNS json
 AS $$
    import json
    json_data = json.loads(data)
    json_data[key] = value
    return json.dumps(json_data, indent=4)
 $$ LANGUAGE plpythonu;

-- Check how JSON looks before updating

SELECT json_update(content::json, 'CFRDiagnosis.mod_nbs', '1')
FROM sc_server_centre_document WHERE record_id = 35 AND template = 'CFRDiagnosis';

-- Once satisfied update JSON inplace

UPDATE sc_server_centre_document SET content = json_update(content::json, 'CFRDiagnosis.mod_nbs', '1')
WHERE record_id = 35 AND template = 'CFRDiagnosis';

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

这似乎在PostgreSQL 9.5上有效

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';