Postgresql按查询分组以转换json格式

我的表格数据如下

_身份证 产品标识 产品名称 卖出价 购买价格 国家 1. 珠三角1 产品一 15 12 美国 2. 珠三角1 产品一 16 13 加拿大 3. 珠三角2 产品二 7. 5. 中国 4. 珠三角2 产品二 12 10 日本

---

你很接近。只需将整个内容包装在另一个

json\u agg（）

中，即可将其合并为一行：

edb=# select jsonb_pretty(json_agg(tb)::jsonb) from (
  select _id, json_agg(obj) as details
  from (
    select product_id as _id, json_build_object(
           '_id', _id,
           'product_id', product_id,
           'product_name', product_name,
           'sell_price', sell_price,
           'purchase_price', purchase_price,
           'country', country
         ) as obj
    from products p) tmp
    group by _id) as tb;
                  jsonb_pretty                  
------------------------------------------------
 [                                             +
     {                                         +
         "_id": "prd_2",                       +
         "details": [                          +
             {                                 +
                 "_id": 3,                     +
                 "country": "china",           +
                 "product_id": "prd_2",        +
                 "sell_price": 7,              +
                 "product_name": "product two",+
                 "purchase_price": 5           +
             },                                +
             {                                 +
                 "_id": 4,                     +
                 "country": "japan",           +
                 "product_id": "prd_2",        +
                 "sell_price": 12,             +
                 "product_name": "product two",+
                 "purchase_price": 10          +
             }                                 +
         ]                                     +
     },                                        +
     {                                         +
         "_id": "prd_1",                       +
         "details": [                          +
             {                                 +
                 "_id": 1,                     +
                 "country": "usa",             +
                 "product_id": "prd_1",        +
                 "sell_price": 15,             +
                 "product_name": "product one",+
                 "purchase_price": 12          +
             },                                +
             {                                 +
                 "_id": 2,                     +
                 "country": "canada",          +
                 "product_id": "prd_1",        +
                 "sell_price": 16,             +
                 "product_name": "product one",+
                 "purchase_price": 13          +
             }                                 +
         ]                                     +
     }                                         +
 ]
(1 row)