mysql-connector python'IN'运算符存储为列表 [英] mysql-connector python 'IN' operator stored as list

问题描述

我正在将mysql-connector与python结合使用，并有这样的查询:

I am using mysql-connector with python and have a query like this:

SELECT avg(downloadtime) FROM tb_npp where date(date) between %s and %s and host like %s",(s_date,e_date,"%" + dc + "%")

现在，如果我的变量"dc"是这样的列表:

NOw, if my variable 'dc' is a list like this:

 dc = ['sjc','iad','las']

然后我有一个如下所示的mysql查询:

Then I have a mysql query like below:

SELECT avg(downloadtime) FROM tb_npp where date(date) = '2013-07-01' and substring(host,6,3) in ('sjc','las');

我的问题是，如何在我的python代码中编写此查询，该查询会将变量"dc"转换为列表?

My question is, how do I write this query in my python code which will convert my variable 'dc' to a list?

我尝试了以下查询，但出现错误:处理格式参数失败； "MySQLConverter"对象没有属性"_list_to_mysql"

I tried the below query but getting error: Failed processing format-parameters; 'MySQLConverter' object has no attribute '_list_to_mysql'

cursor3.execute("SELECT avg(downloadtime) FROM tb_npp where date(date) between %s and %s and substring(host,6,3) in %s",(s_date,e_date,dc))

有人可以告诉我我在做什么错吗?

Can somebody please tell me what I am doing wrong?

预先感谢

推荐答案

我不熟悉mysql-connector，但是它的行为似乎是

I'm not familiar with mysql-connector, but its behavior appears to be similar to MySQLdb in this regard. If that's true, you need to use a bit of string formatting:

sql = """SELECT avg(downloadtime) FROM tb_npp where date(date) = %s 
         and substring(host,6,3) in ({c})""".format(
            c=', '.join(['%s']*len(dc)))    
args = ['2013-07-01'] + dc
cursor3.execute(sql, args)

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