sql - 如何查询 postgres json 列中的嵌套数组？

Question

我有一些类似于下面的 json 的 json 存储在 postgres json 列中。我正在尝试查询它以识别一些错误输入的数据。我基本上是在寻找房屋描述与门牌号相同的地址。我不太清楚该怎么做。

{
  "timestamp": "2014-10-23T16:15:28+01:00",
  "schools": [
    {
    "school_id": "1",
    "addresses": [
      {
        "town": "Birmingham",
        "house_description": "1",
        "street_name": "Parklands",
        "addr_id": "4",
        "postcode": "B5 8KL",
        "house_no": "1",
        "address_type": "UK"
      },
      {
        "town": "Plymouth",
        "house_description": "Flat a",
        "street_name": "Fore Street",
        "addr_id": "2",
        "postcode": "PL9 8AY",
        "house_no": "15",
        "address_type": "UK"
      }
    ]
  },
  {
    "school_id": "2",
    "addresses": [
      {
        "town": "Coventry",
        "street_name": "Shipley Way",
        "addr_id": "19",
        "postcode": "CV8 3DL",
        "house_no": "662",
        "address_type": "UK"
      }
    ]
  }
  ]
}

我写了这个 sql，它将找到数据匹配的位置:

select *
FROM title_register_data
where address_data->'schools'->0->'addresses'->0->>'house_description'= 
address_data->'schools'->0->'addresses'->0->>'house_no'

这显然只适用于第一所学校的第一个地址。有没有办法查询每所学校的所有地址？

Answer 1

横向使用jsonb_array_elements()，加入与你想要比较的元素的json数组深度一样多的次数:

select 
    schools->>'school_id' school_id,
    addresses->>'addr_id' addr_id,
    addresses->>'house_description' house_description,
    addresses->>'house_no' house_no
from title_register_data,
jsonb_array_elements(address_data->'schools') schools,
jsonb_array_elements(schools->'addresses') addresses
where addresses->>'house_description' = addresses->>'house_no';

 school_id | addr_id | house_description | house_no 
-----------+---------+-------------------+----------
 1         | 4       | 1                 | 1
(1 row)