[英]Search by date in array of objects within PostgreSQL JSONB Column
I have two tables in my PostgreSQL 9.6 instance.我的 PostgreSQL 9.6 实例中有两个表。
users
+----+------------+-----------+-------------------+
| id | first_name | last_name | email |
+----+------------+-----------+-------------------+
| 1 | John | Doe | john.doe@test.com |
+----+------------+-----------+-------------------+
| 2 | Jane | Doe | jane.doe@test.com |
+----+------------+-----------+-------------------+
| 3 | Mike | Doe | mike.doe@test.com |
+----+------------+-----------+-------------------+
surveys
+----+---------+----------------------------------------------------------------------------------------------------+
| id | user_id | survey_data |
+----+---------+----------------------------------------------------------------------------------------------------+
| 1 | 1 | {'child_list': [{'gender': 1, 'birthday': '2015-10-01'}, {'gender': 2, 'birthday': '2017-05-01'}]} |
+----+---------+----------------------------------------------------------------------------------------------------+
| 2 | 2 | {'child_list': []} |
+----+---------+----------------------------------------------------------------------------------------------------+
| 3 | 3 | {'child_list': [{'gender': 2, 'birthday': '2008-01-01'}]} |
+----+---------+----------------------------------------------------------------------------------------------------+
I would like be able to query these two tables to get the number of users who have children between certain age.我希望能够查询这两个表以获取在特定年龄之间有孩子的用户数量。 The
survey_data
column in surveys
table is a JSONB column.该
survey_data
列surveys
表是JSONB列。
So far I've tried using jsonb_populate_recordset
with LATERAL
joins.到目前为止,我已经尝试将
jsonb_populate_recordset
与LATERAL
连接一起使用。 I was able to SELECT
the child_list
array as two columns but couldn't figure out how to use that with my JOIN
between users
and surveys
tables.我能够将
child_list
数组SELECT
为两列,但无法弄清楚如何在users
和surveys
表之间使用我的JOIN
。 The query I used is as below:我使用的查询如下:
SELECT DISTINCT u.email
FROM surveys
CROSS JOIN LATERAL (
SELECT *
FROM jsonb_populate_recordset(null::json_type, (survey.survey_data->>'child_list')::jsonb) AS d
) d
INNER JOIN users u ON u.id = survey.user_id
WHERE d.birthday BETWEEN '2014-05-05' AND '2018-05-05';
This also uses a custom type which was created using this:这也使用了使用此创建的自定义类型:
CREATE type json_type AS (gender int, birthday date)
My question is, is there an easier to read way to do this?我的问题是,有没有更容易阅读的方法来做到这一点? I would like to use this query with many other
JOIN
s and WHERE
clauses and I was wondering if there is a better way of doing this.我想将此查询与许多其他
JOIN
和WHERE
子句一起使用,我想知道是否有更好的方法来做到这一点。
Note: this is mainly going to be used by a reporting system which does not need to be super fast but of course any speed gains are welcome.注意:这主要由不需要超快但当然欢迎任何速度提升的报告系统使用。
Use the function jsonb_array_elements(),
examples:使用函数
jsonb_array_elements(),
示例:
select email, (elem->>'gender')::int as gender, (elem->>'birthday')::date as birthday
from users u
left join surveys s on s.user_id = u.id
cross join jsonb_array_elements(survey_data->'child_list') as arr(elem)
email | gender | birthday
-------------------+--------+------------
john.doe@test.com | 1 | 2015-10-01
john.doe@test.com | 2 | 2017-05-01
mike.doe@test.com | 2 | 2008-01-01
(3 rows)
or或者
select distinct email
from users u
left join surveys s on s.user_id = u.id
cross join jsonb_array_elements(survey_data->'child_list') as arr(elem)
where (elem->>'birthday')::date between '2014-05-05' and '2018-05-05';
email
-------------------
john.doe@test.com
(1 row)
You can make your life easier using a view:您可以使用视图让您的生活更轻松:
create view users_children as
select email, (elem->>'gender')::int as gender, (elem->>'birthday')::date as birthday
from users u
left join surveys s on s.user_id = u.id
cross join jsonb_array_elements(survey_data->'child_list') as arr(elem);
select distinct email
from users_children
where birthday between '2014-05-05' and '2018-05-05';
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