Sql 使用多个数组和分组方式更改Postgres选择
我在postgres 9.3中编写SQL,它几乎可以完美地工作:Sql 使用多个数组和分组方式更改Postgres选择,sql,postgresql,Sql,Postgresql,我在postgres 9.3中编写SQL,它几乎可以完美地工作: SELECT type_id, to_json(array_agg(row(value, id))) AS json FROM sub_types GROUP BY type_id 结果表如下所示: type_id | json 1 | [{"f1":"something", "f2":7}, ...] 2 | [{"f1":"something new", "f2":2}, ...] 我正在尝试这样做
SELECT type_id, to_json(array_agg(row(value, id))) AS json FROM sub_types GROUP BY type_id
结果表如下所示:
type_id | json
1 | [{"f1":"something", "f2":7}, ...]
2 | [{"f1":"something new", "f2":2}, ...]
我正在尝试这样做,结果如下所示:
type_id | json
1 | [{"value":"something", "id":7}, ...]
2 | [{"value":"something new", "id":2}, ...]
基本思想是编写代码(PHP),类似于:
行=pdo_调用_选择
rows = pdo_call_select
foreach (rows as row)
{
print '<span data-id="row->id">'
foreach (row->json as otherfields)
print '<input value="otherfields->value" ...'
...
我为所有json结果创建类型,并将行转换为该类型
create table sub_types (
id int, type_id int, value text
);
create type sub_json_type as (value text, id integer);
insert into sub_types (id, type_id, value) values
(1, 3, 'something'),
(2, 2, 'blabla'),
(3, 3, 'something new'),
(4, 1, 'ok');
SELECT type_id, to_json(array_agg(row(value, id)::sub_json_type)) AS json FROM sub_types GROUP BY type_id;
type_id | json
---------+-----------------------------------------------------------------
1 | [{"value":"ok","id":4}]
2 | [{"value":"blabla","id":2}]
3 | [{"value":"something","id":1},{"value":"something new","id":3}]
(3 rows)
create table sub_types (
id int, type_id int, value text
);
insert into sub_types (id, type_id, value) values
(1, 3, 'something'),
(2, 2, 'blabla'),
(3, 3, 'something new'),
(4, 1, 'ok');
select type_id, json_agg(row_to_json(cj)) as json
from
sub_types st
cross join lateral
(select value, id) cj
group by type_id
;
type_id | json
---------+------------------------------------------------------------------
1 | [{"value":"ok","id":4}]
3 | [{"value":"something","id":1}, {"value":"something new","id":3}]
2 | [{"value":"blabla","id":2}]
create table sub_types (
id int, type_id int, value text
);
create type sub_json_type as (value text, id integer);
insert into sub_types (id, type_id, value) values
(1, 3, 'something'),
(2, 2, 'blabla'),
(3, 3, 'something new'),
(4, 1, 'ok');
SELECT type_id, to_json(array_agg(row(value, id)::sub_json_type)) AS json FROM sub_types GROUP BY type_id;
type_id | json
---------+-----------------------------------------------------------------
1 | [{"value":"ok","id":4}]
2 | [{"value":"blabla","id":2}]
3 | [{"value":"something","id":1},{"value":"something new","id":3}]
(3 rows)