SQL异常处理

connection = mysql.connector.connect(
    =====)

为什么不放在try之前？

try:
    connection = mysql.connector.connect(
        host='localhost',
        port=3307,
        user='root',
        password='HT103066@lzs',
        database='test'
    )
    connection.start_transaction()
    cursor=connection.cursor()
    sql="INSERT INTO account(name,money) VALUES(%s,%s)"
    cursor.execute(sql,('王麻子',3500))
    connection.commit()
except Exception as e:
    if "connection" in dir():
        connection.rollback()
    print("错误原因是：%s"%e)
finally:
    if "connection" in dir():
        connection.close()