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[英]Appending (pushing) and removing from a JSON array in PostgreSQL 9.5+
[英]Appending (pushing) and removing from a JSON array in PostgreSQL 9.2, 9.3, and 9.4?
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。
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。
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;
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