python 检测数据库是否可以正常连接

1. 代码

import pymysql.cursors


if __name__ == "__main__":
    # 连接数据库
    connect = pymysql.Connect(host='28.104.87.149', port=3306, user='root', passwd='123456', db='weekreport', charset='utf8')

    # 获取游标
    cursor = connect.cursor()

    # 插入数据
    sql = "INSERT INTO trade (name, account, saving) VALUES ( '%s', '%s', %.2f )"
    data = ('雷军', '13512345678', 10000)
    cursor.execute(sql % data)
    connect.commit()
    print('成功插入', cursor.rowcount, '条数据')

    # 修改数据
    sql = "UPDATE trade SET saving = %.2f WHERE account = '%s' "
    data = (8888, '13512345678')
    cursor.execute(sql % data)
    connect.commit()
    print('成功修改', cursor.rowcount, '条数据')

    # 查询数据
    sql = "SELECT name,saving FROM trade WHERE account = '%s' "
    data = ('13512345678',)
    cursor.execute(sql % data)
    for row in cursor.fetchall():
        print("Name:%s\tSaving:%.2f" % row)
    print('共查找出', cursor.rowcount, '条数据')

    # 删除数据
    sql = "DELETE FROM trade WHERE account = '%s' LIMIT %d"
    data = ('13512345678', 1)
    cursor.execute(sql % data)
    connect.commit()
    print('成功删除', cursor.rowcount, '条数据')

    # 事务处理
    sql_1 = "UPDATE trade SET saving = saving + 1000 WHERE account = '18012345678' "
    sql_2 = "UPDATE trade SET expend = expend + 1000 WHERE account = '18012345678' "
    sql_3 = "UPDATE trade SET income = income + 2000 WHERE account = '18012345678' "

    try:
        cursor.execute(sql_1)  # 储蓄增加1000
        cursor.execute(sql_2)  # 支出增加1000
        cursor.execute(sql_3)  # 收入增加2000
    except Exception as e:
        connect.rollback()  # 事务回滚
        print('事务处理失败', e)
    else:
        connect.commit()  # 事务提交
        print('事务处理成功', cursor.rowcount)

    # 关闭连接
    cursor.close()
    connect.close()