如何通过SQL PL / JSON生成JSON

问题描述

我正在尝试使用PL / JSON从SQL生成JSON

declare 
      customer json_list := json_list();
      product json_list;

begin
  customer:= json_dyn.executeList('SELECT DISTINCT
  A.customer_id,A.customer_name,FROM customer A
  WHERE A.customer_id = 1');
  
  product := json_dyn.executeList('SELECT DISTINCT
  A.product_id,A.product_name,FROM sales A
  INNER JOIN customer B
  ON A.customer_id = B.customer_id
  WHERE A.customer_id = 1');

end;

我需要将这两个选择合并为一个JSON，如下所示： 在某种程度上，产品是销售的关键，产品的价值是产品的列表

[
  {
    "customer_id": 1,"customer_name": "Customer A","product": [
      {
        "product_id": 5715,"product_name": "Product A",},{
        "product_id": 7841,"product_name": "Product B",}
    ]
  }
]

有人知道怎么做吗？

解决方法

declare

   v_customers pljson_list := pljson_list();
   v_customer  pljson;
   v_products  pljson_list;

begin

   for c in (select distinct customer_id,customer_name
               from customer
              where customer_id = 1) loop

      v_customer := pljson();
      v_customer.put('customer_id',c.customer_id);
      v_customer.put('customer_name',c.customer_name);

      v_products := json_dyn.executeList('select distinct product_id,product_name
                                            from sales
                                           where customer_id = ' || c.customer_id);
      v_customer.put('products',v_products.to_json_value);

      v_customers.append(v_customer.to_json_value);

   end loop;

end;

在此代码段中，我使用了pljson类型（最新版本为https://github.com/pljson/pljson）：如果您使用的是旧版本的库，则用“ json”替换任何出现的“ pljson”应该就足够了（但是我建议升级，否则您在Oracle 18或更高版本上可能会遇到问题。

,

我想“列表”来自某个表：

declare

   v_customers pljson_list := pljson_list();
   v_products  pljson_list;
   v_lists     pljson_list;
   v_customer  pljson;
   v_product   pljson;

begin

   for c in (select distinct customer_id,c.customer_name);

      v_products := pljson_list();

      for p in (select distinct product_id,product_name
                  from sales
                 where customer_id = c.customer_id) loop

         v_product := pljson();
         v_product.put('product_id',p.product_id);
         v_product.put('product_name',p.product_name);

         v_lists := json_dyn.executeList('select distinct a,b
                                            from lists
                                           where product_id = ' || p.product_id);
         v_product.put('list',v_lists.to_json_value);

         v_products.append(v_product.to_json_value);

      end loop;

      v_customer.put('products',v_products.to_json_value);

      v_customers.append(v_customer.to_json_value);

   end loop;

end;

HTH。

,

@archimede，就是列表中的一个列表

{
    "customer_id": 1,"customer_name": "Customer A","product": [
        {
            "product_id": 5715,"product_name": "Product A","list" : [
                {
                    "a" : 1,"b": 2
                },{
                    "a" : 10,"b" : 20
                }
            ]
        }
    ]
}