Question

我有一个名为cust_data的表，它存储id和JSON对象。我想编写postgres select语句来获取：

选择所有ID的“性别”：人员阵列中不存在“女性”[这应该从以下数据返回ID＃3]
选择所有ID，其中“性别”：“女性”存在，“状态”：“已婚”[这应该从以下数据返回ID＃2]

表：cust_data

id(numeric) | connections (jsonb)
------------------------------

1, {"Persons": [
            {
              "personName": "Tom",
              "gender": "Male",
              "country": "USA",
              "status":"single"

            },
            {
            "personName": "Harry",
            "gender": "Male",
            "country": "USA",
            "status":"single"
            },
            {
            "personName": "Lisa",
            "gender": "Female",
            "country": "Mexico",
            "status":"single"
              }    
          ]
        }

        2,{
          "Persons": [
            {
              "personName": "Lisa",
              "gender": "Male",
              "country": "UK",
              "status":"single"
            },
            {
            "personName": "Harry",
            "gender": "Male",
            "country": "USA",
            "status":"single"
            },
            {
            "personName": "Lisa",
            "gender": "Female",
            "country": "Mexico",
            "status":"married"
              }    
          ]
        }

        3,{
          "Persons": [
            {
              "personName": "Lisa",
              "gender": "Male",
              "country": "UK",
              "status":"single"
            },
            {
            "personName": "Harry",
            "gender": "Male",
            "country": "USA",
            "status":"single"
            }   
          ]
        }

Answer 1

您可以使用boolean aggregate functions：

select id
from cust_data,
lateral jsonb_array_elements(connections->'Persons')
group by 1
having not bool_or(value->>'gender' = 'Female');

 id 
----
  3
(1 row)

select id
from cust_data,
lateral jsonb_array_elements(connections->'Persons')
group by 1
having bool_or(value->>'gender' = 'Female' and value->>'status' = 'married');

 id 
----
  2
(1 row)

Test it here.

如果数组可能为空，则应使用left join ... on true代替lateral。也为coalesce()添加适当的聚合默认值，因为它们可以产生null，例如：

select id
from cust_data
left join jsonb_array_elements(connections->'Persons') on true
group by 1
having not coalesce(bool_or(value->>'gender' = 'Female'), false);

Answer 2

查询1：

WITH test AS (
    SELECT id, jsonb_array_elements(t.connections->'Persons') AS elem
    FROM cust_data  t
), findFemale AS (
    SELECT DISTINCT id FROM test
   WHERE elem->>'gender' = 'Female'
) 
SELECT id FROM cust_data
WHERE id NOT IN  (select * from findFemale)

查询2：

 WITH test as (SELECT id, jsonb_array_elements(t.connections->'Persons') AS elem  
 from cust_data   t
 ) , findFemaleMarried as (
 select distinct id from test
 where 
 elem ->> 'gender' = 'Female' and elem ->> 'status' = 'married'
 )
 select * from findFemaleMarried

我希望以上查询可以解决您的问题。

Postgres查询JSON数组

2 个答案: