在PostgreSQL 9.2,9.3和9.4中追加(推送)和删除JSON数组？

Question

对于大于9.5的版本,请参阅此问题

我使用这个在PostgreSQL中创建了一个表:

CREATE TEMP TABLE jsontesting
AS
  SELECT id, jsondata::jsonb FROM ( VALUES
    (1, '["abra","value","mango", "apple", "sample"]'),
    (2, '["japan","china","india", "russia", "australia"]'),
    (3, '["must", "match"]'),
    (4, '["abra","value","true", "apple", "sample"]'),
    (5, '["abra","false","mango", "apple", "sample"]'),
    (6, '["string","value","mango", "apple", "sample"]'),
    (7, '["must", "watch"]')
  ) AS t(id,jsondata);

现在我想要的是

• 添加像append_to_json_array这样的东西,实际的jsondata是一个json数组,而newString是我必须添加到jsondata数组的,这个函数应该返回更新的json数组.

  UPDATE jsontesting
  SET jsondata=append_to_json_array(jsondata, 'newString')
  WHERE id = 7;
  

• 从json数据数组中删除一个值,一个用于删除值的函数.

我试图搜索postgreSQL的文档,但没有发现任何内容.

Answer 1

拉德克的想法可以用来定义这些方便的功能:

create function jsonb_array_append(j jsonb, e text)
returns jsonb language sql immutable
as $$
    select array_to_json(array_append(array(select * from jsonb_array_elements_text(j)), e))::jsonb 
$$;

create function jsonb_array_remove(j jsonb, e text)
returns jsonb language sql immutable
as $$
    select array_to_json(array_remove(array(select * from jsonb_array_elements_text(j)), e))::jsonb 
$$;

create function jsonb_array_replace(j jsonb, e1 text, e2 text)
returns jsonb language sql immutable
as $$
    select array_to_json(array_replace(array(select * from jsonb_array_elements_text(j)), e1, e2))::jsonb 
$$;

行动中的功能:

select jsonb_array_append('["alfa", "beta", "gamma"]', 'delta');
         jsonb_array_append
------------------------------------
 ["alfa", "beta", "gamma", "delta"]

select jsonb_array_remove('["alfa", "beta", "gamma"]', 'beta');
 jsonb_array_remove
-------------------
 ["alfa", "gamma"]

select jsonb_array_replace('["alfa", "beta", "gamma"]', 'alfa', 'delta');
     jsonb_array_replace
----------------------------
 ["delta", "beta", "gamma"]

如果他们证明对你有用,请欣赏拉德克的回答.但是,我必须补充一点,我完全赞同a_horse的评论.

Answer 2

加上：

update jsontesting 
set jsondata = array_to_json(array(select * from jsonb_array_elements_text(jsondata)) || 'newString'::text)::jsonb 
where id = 7;

去除：

update jsontesting 
set jsondata = array_to_json(array_remove(array(select * from jsonb_array_elements_text(jsondata)), 'toRemove'))::jsonb 
where id = 7;