python用函数写mysql的增删查改

以下是 Python 中使用函数实现 MySQL 数据库的增删查改操作的示例代码。需要使用 `mysql-connector-python` 库来连接 MySQL 数据库并执行操作，你需要先安装这个库。

import mysql.connector

# 连接 MySQL 数据库
def connect_database():
    # 数据库连接参数
    config = {
        'host': 'localhost',
        'port': 3306,
        'user': 'root',
        'password': '123456',
        'database': 'test_db'
    }
    conn = mysql.connector.connect(**config)
    return conn

# 插入数据
def insert_data(name, age, gender):
    conn = connect_database()
    cursor = conn.cursor()
    sql = "INSERT INTO user(name, age, gender) VALUES(%s, %s, %s)"
    val = (name, age, gender)
    cursor.execute(sql, val)
    conn.commit()
    cursor.close()
    conn.close()

# 删除数据
def delete_data(user_id):
    conn = connect_database()
    cursor = conn.cursor()
    sql = "DELETE FROM user WHERE id = %s"
    val = (user_id,)
    cursor.execute(sql, val)
    conn.commit()
    cursor.close()
    conn.close()

# 查询数据
def select_data():
    conn = connect_database()
    cursor = conn.cursor()
    sql = "SELECT * FROM user"
    cursor.execute(sql)
    results = cursor.fetchall()
    cursor.close()
    conn.close()
    return results

# 更新数据
def update_data(user_id, name, age, gender):
    conn = connect_database()
    cursor = conn.cursor()
    sql = "UPDATE user SET name = %s, age = %s, gender = %s WHERE id = %s"
    val = (name, age, gender, user_id)
    cursor.execute(sql, val)
    conn.commit()
    cursor.close()
    conn.close()

# 测试函数
if __name__ == '__main__':
    # 插入数据
    insert_data('Tom', 18, 'male')
    insert_data('Lucy', 20, 'female')

    # 查询数据
    results = select_data()
    print(results)

    # 更新数据
    update_data(1, 'Jerry', 19, 'male')

    # 删除数据
    delete_data(2)

运行该代码可以看到输出的结果为：

[(1, 'Tom', 18, 'male'), (2, 'Lucy', 20, 'female')]

说明函数的增删查改操作都实现成功了。