以 JSON 格式返回 Oracle 查询结果

Question

我想创建一个 python 脚本来运行 oracle 查询并将每个结果行存储到 JSON 文件中。 到目前为止，我已经完成了 oracle 连接、查询执行和每个结果行的打印。

注意：我正在使用cx_Oracle

import cx_Oracle

try:
    con = cx_Oracle.connect('username/pass@127.0.0.1/oracle')
except cx_Oracle.DatabaseError as er:
    print('There is an error in the Oracle database:', er)

else:
    try:
        cur = con.cursor()

        # fetchall() is used to fetch all records from result set
        cur.execute('select * from products')
        rows = cur.fetchall()
        print(rows)


    except cx_Oracle.DatabaseError as er:
        print('There is an error in the Oracle database:', er)

    except Exception as er:
        print('Error:'+str(er))

    finally:
        if cur:
            cur.close()
finally:
    if con:
        con.close()

以下是所需的 JSON output：

product_json

{
    "arrayOfProducts": [
        {
            "id": 1,
            "name": "CHECK PRINT SHIRT",
            "price": 110
        },
        {
            "id": 2,
            "name": "GLORIA HIGH LOGO SNEAKER",
            "price": 91
        },
        {
            "id": 3,
            "name": "CATE RIGID BAG",
            "price": 94.5
        },
        {
            "id": 4,
            "name": "GUESS CONNECT WATCH",
            "price": 438.9
        }
    ]
}

Answer 1

您可以使用以下方法从数据库中获取 JSON，而不是使用select * from products ：

SELECT JSON_OBJECT(
         KEY 'arrayOfProducts'
         VALUE JSON_ARRAYAGG(
           JSON_OBJECT(
             KEY 'id'    VALUE id,
             KEY 'name'  VALUE name,
             KEY 'price' VALUE price
             -- RETURNING CLOB PRETTY
           )
           -- RETURNING CLOB PRETTY
         )
         -- RETURNING CLOB PRETTY
       ) AS json
FROM   products

（注意：如果您希望它使用空格格式化，请取消注释RETURNING CLOB PRETTY行。）

其中，对于样本数据：

CREATE TABLE products (id, name, price) AS
SELECT 1, 'name1', 110   FROM DUAL UNION ALL
SELECT 2, 'name2',  91   FROM DUAL UNION ALL
SELECT 3, 'name3',  94.5 FROM DUAL UNION ALL
SELECT 4, 'name4', 438.9 FROM DUAL;

输出：

JSON
{"arrayOfProducts":[{"id":1,"name":"name1","price":110},{"id":2,"name":"name2","price":91}, {"id":3,"name":"name3","price":94.5},{"id":4,"name":"name4","price":438.9}]}

db<> 在这里摆弄