sth about MySQLdb

gistfile1.py

# -*- coding: utf-8 -*-


import MySQLdb

#(1, 2, 3, 'final', 0)
print MySQLdb.version_info

'''
+--------------------+
|id    | email       |
+------+-------------+
|admin | xxx@123.com |
+------+-------------+
'''

conn = MySQLdb.Connection(host='localhost', user='test', passwd='', db='Chi')
cursor = conn.cursor()

#确认数据存在
cursor.execute('select * from `User` where id = %s', ('admin', ))
print cursor.fetchall()

#碰巧最后的 SQL 是正确的, 不报错
id_list = [1, 2]
cursor.execute('select * from `User` where id in %s', (id_list, ))
print cursor.fetchall()

#这样就没那么巧了
#id_list = [1]
#cursor.execute('select * from `User` where id in %s', (id_list, ))
#print cursor.fetchall()

#碰巧的 SQL 只对整数有效, 下面的查询并不会得到正确的结果
id_list = ['1', 'admin']
cursor.execute('select * from `User` where id in %s', (id_list, ))
print cursor.fetchall()

#似乎没有比下面更好的办法了
#其实看 django 的 ORM 也可以看出它生成的 SQL 就是这样的
id_list = ['1', 'admin']
cursor.execute('select * from `User` where id in (%s)' % ','.join(['%s'] * len(id_list)),
               id_list)
print cursor.fetchall()