Question

我的查询是

select array_to_json(array_agg(row_to_json(t))) from (
    select count(*) over() as total, id,title
    FROM notifications 
    WHERE  title ilike '%a%'
LIMIT 5 OFFSET 1)t

，输出

[
    {
        "title": "Sartaj                                                              ", 
        "id": 3,
        "total":16
    }
]

结果包括对象中的总数，但我想将它移到对象之外。

我的预期答案是

[
    "total":16,
    "data":[
{
        "title": "Sartaj                                                       ", 
        "id": 3
    }]
 ]

我也试过

with tmp_notifications as (
    SELECT id,title,description,img_url,link,created_on from notifications 
    where title ilike '%universi%'
    ) 
    select row_to_json(t) from (
        select count(*) as data_count,
        (json_agg(json_build_object('description',description,'title',title,'created_on',created_on,
        'link',link,'img_url',img_url,'id',id)) 
         ) as data from tmp_notifications limit 1
        )t

但限制在这里不起作用。

Answer 1

使用json_build_object()和json_agg()：

private static class LazyResourceHolder {
  public static Resource resource = new Resource();
}

...

public static Resource getInstance() {
  return LazyResourceHolder.something;
}

请参阅DbFiddle.

中的完整示例

您可以使用select json_build_object('total', count(*), 'data', json_agg(to_json(t))) from ( select id, title from notifications where title ilike '%a%' ) t语句计算所有已过滤的行，但会显示其数量有限，例如：

WITH

DbFiddle.

计算所有行并在单个json对象中显示有限数量的行

1 个答案: