为什么我的 class 没有从 select 返回数据？

Question

我正在学习类，并尝试编写一个连接和 select 来自我的数据库。有没有更好的方法来做到这一点，或者我只是在某处缺少 return ？ select 数据未 returning。

import psycopg2
class MyData():
    def __init__(self, host="10.0.66.60", db="db", user="postgres", password="Secret"):
        self.conn = psycopg2.connect(host=host, database=db, user=user, password=password)
            self.cur = self.conn.cursor()
    
    def query(self, query):
        self.cur.execute(query)
            
    def close(self):
        self.cur.close()
        self.conn.close()
    
db = MyData()
db.query("SELECT * FROM detail;")
db.close()

Answer 1

import psycopg2
class MyData():
    def __init__(self, host="10.0.66.60", db="db", user="postgres", password="Secret"):
        self.conn = psycopg2.connect(host=host, database=db, user=user, password=password)
            self.cur = self.conn.cursor()
    
    def query(self, query):
        self.cur.execute(query)

        # you need fetchall or fetchone to get the data, eg:
        result = self.cur.fetchall()
        for row in result:
            print(row)
        # ref: https://www.psycopg.org/docs/cursor.html#cursor.fetchall
            
    def close(self):
        self.cur.close()
        self.conn.close()
    
db = MyData()
db.query("SELECT * FROM detail;")
db.close()

为什么我的 class 没有从 select 返回数据？

Why is my class not returning data from a select?

python

class

psycopg2