Python参数化查询

Question

我正在尝试创建一个简单的脚本来更改mysql数据，但我对参数化查询有点困惑。代码如下所示：

reader_id = sys.argv[1]
cmd_id = sys.argv[2]

conn = mysql.connect(user='...', passwd='...', host='...', db='...')
curs = conn.cursor()

mysql_data = {
    "reader_id": int(reader_id),
    "cmd_id": int(cmd_id)
}

curs.execute("UPDATE `reader_config_hw` SET `changed_` = '1' "
             "WHERE `object_id` = %(reader_id)d AND `id` = %(cmd_id)d;", mysql_data)

curs.execute("UPDATE `reader` SET `check_for_command` = '1' WHERE `id` = %(reader_id)d", mysql_data)

错误结果是

Traceback (most recent call last):
  File "./main.py", line 25, in <module>
    "WHERE `object_id` = %(reader_id)d AND `id` = %(cmd_id)d;", mysql_data)
  File "/usr/lib64/python3.6/site-packages/MySQLdb/cursors.py", line 210, in execute
    query = query % args
TypeError: %d format: a number is required, not str

它说这个数字是必需的，但是我已经用int(reader_id)改变了变量的类型，对吗？

Answer 1

试着改变"WHERE 'object_id' = %(reader_id)d AND 'id' = %(cmd_id)d;"

至

"WHERE 'object_id' = %(reader_id)s AND 'id' = %(cmd_id)s;"

我认为变量调用后的'd‘表示一个“数字”，而您需要使用字符串。

编辑：为了澄清，可以在MySQL查询中使用字符串来代替整数