在PostgreSQL中使用类似JOIN的语句合并JSONB字段的嵌套ARRAY?

时间:2018-02-26 16:53:14

标签: arrays postgresql merge nested jsonb

鉴于此表:

图书

 id | data
----+-------------------------------------------------------
 1  | { title: 'Book 1', price: 10.5, authors: [{ id: 1}, { id: 2 }]}
 2  | { title: 'Book 2', price: 11.5, authors: [{ id: 2 } }

AUTHORS

 id | data
-----+-------------------------------------------------------
 1  | { name: 'Author 1', address: 'Address author 1' }
 2  | { name: 'Author 2', address: 'Address author 2' }

是否可以通过将authors键数组元素与类似JOIN的语句或使用jsonb函数合并来获得此结果?

预订查询结果

 id | data
----+------------------------------------------------------------------------------------------------------
 1  | { title: 'Book 1', price: 10.5, authors: [{ id: 1, name: 'Author 1', address: 'Address author 1' }, { id: 2, name: 'Author 2', address: 'Address author 2'}] }
 2  | { title: 'Book 2', price: 11.5, authors: [{ id: 2, name: 'Author 2', address: 'Address author 2'}] }

由于

1 个答案:

答案 0 :(得分:0)

select b.data || jsonb_build_object('authors', jsonb_agg(a.data || 
jsonb_build_object('id', a.id)))
from books b
left join (select id, jsonb_array_elements(data->'authors') from books) ba on 
ba.id = b.id
left join authors a on a.id = ba.id
group by b.id;