在另一个查询的 select 中查询一个 jsonb 数组

Question

我有一个用户 table 有一个收藏夹列是 jsonb

favorites:
 [
        {
            "id_doc:": 9,
            "type": "post"
        },
        {
            "id_doc": 10,
            "type": "post"
        }
 ]

我还有另一个 table 帖子，我想通过 id 进行查询，这个 id 必须在收藏夹用户

的 id_doc 字段中

select * from posts where id in (select favorites -> id_doc from users )

这是架构

CREATE TABLE dev.users
(
    id integer NOT NULL GENERATED BY DEFAULT AS IDENTITY ( INCREMENT 1 START 1 MINVALUE 1 MAXVALUE 2147483647 CACHE 1 ),
    firstname character varying COLLATE pg_catalog."default" NOT NULL,
    lastname character varying COLLATE pg_catalog."default" NOT NULL,
    email character varying COLLATE pg_catalog."default" NOT NULL,
    password character varying COLLATE pg_catalog."default" NOT NULL,
    favorites jsonb[],
    CONSTRAINT users_pkey PRIMARY KEY (id),
    CONSTRAINT email_key UNIQUE (email)
)
WITH (
    OIDS = FALSE
)
TABLESPACE pg_default;

ALTER TABLE dev.users
    OWNER to postgres;


CREATE TABLE dev.posts
(
    id integer NOT NULL DEFAULT nextval('dev.posts_id_seq'::regclass),
    title character varying COLLATE pg_catalog."default" NOT NULL,
    userid integer NOT NULL,
    description character varying COLLATE pg_catalog."default" NOT NULL,
    CONSTRAINT posts_pkey PRIMARY KEY (id)
)
WITH (
    OIDS = FALSE
)
TABLESPACE pg_default;

ALTER TABLE dev.posts
    OWNER to postgres;

我该怎么做？谢谢

Answer 1

还有其他方法可以实现此目的，但为了清楚起见，我更喜欢使用 CTE。如果您对此功能有疑问，请在评论中告诉我。

with elements as (
  select jsonb_array_elements(favorites) as favitem
    from users
), fav_ids as (
  select distinct (favitem->>'id_doc')::int as id_doc
    from elements
)
select p.*
  from posts p
  join fav_ids f on f.id_doc = p.id
;

更新由于列定义为 jsonb[] 而不是 json，我们需要 unnest() 而不是 jsonb_array_elements():

with elements as (
  select unnest(favorites) as favitem
    from users
), fav_ids as (
  select distinct (favitem->>'id_doc')::int as id_doc
    from elements
)
select p.*
  from posts p
  join fav_ids f on f.id_doc = p.id
;

在另一个查询的 select 中查询一个 jsonb 数组

query a jsonb array in a select of another query

postgresql

postgresql-10