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shezyy
Asked:2023-07-14 03:04:45 +0800 CST2023-07-14 03:04:45 +0800 CST

我不明白如何修复错误 NameError：名称“连接”未定义

  • 772

我开始学习SQL，当我尝试连接到数据库时，出现以下错误NameError：名称'连接'未定义我提供代码：

import psycopg2
from auth_data import host, password, db_name, user


def add_to_db():
    global connection
    try:
        connection = psycopg2.connect(host=host, user=user, password=password, database=db_name)

        with connection.cursor() as cursor:
            cursor.execute(f"SELECT * FROM records")
            connection.commit()
            result = cursor.fetchall()
            return result
    except Exception as _ex:
        print(f'[INFO] Error while working with PostgreSQL {_ex}')
    finally:
        if connection:
            connection.close()
            print(f'[INFO] PostgreSQL connection closed')

add_to_db()
python

2 个回答

  1. 您connection在内部创建try并使用了一个变量，finally因此您需要在这一切之前创建它：

    import psycopg2
from auth_data import host, password, db_name, user


def add_to_db():
    global connection
    connection = None  # <--- Вот здесь

    try:
        connection = psycopg2.connect(host=host, user=user, password=password, database=db_name)

        with connection.cursor() as cursor:
            cursor.execute(f"SELECT * FROM records")
            connection.commit()
            result = cursor.fetchall()
            return result
    except Exception as _ex:
        print(f'[INFO] Error while working with PostgreSQL {_ex}')
    finally:
        if connection:
            connection.close()
            print(f'[INFO] PostgreSQL connection closed')

add_to_db()
    • 2
  2. Best Answer

    现在我尝试重复这段代码。当输入不正确的连接数据时，错误就会消失。所以我建议你检查登录名/密码/数据库等。声明的地点connection不会以任何方式影响执行。

    • 1

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