Python MySQLdb和使用CursorUseResultMixIn的大查询

如何在MySQLdb中使用

CursorUseResultMixIn

。显而易见的是：

con=MySQLdb.connect(host='localhost', user='test', passwd='xx', db='yy')
curs = con.cursor(MySQLdb.cursors.CursorUseResultMixIn)

但这给了我一个错误：

  File "C:\Python26\lib\site-packages\MySQLdb\connections.py", line 226, in cursor
    return (cursorclass or self.cursorclass)(self)
TypeError: object.__new__() takes no parameters

我做错了什么

---

和MySQLdb.cursors模块使用

CursorUseResultMixIn

如下：

class SSCursor(CursorUseResultMixIn, CursorTupleRowsMixIn,
               BaseCursor):

    """This is a Cursor class that returns rows as tuples and stores
    the result set in the server."""

import MySQLdb.cursors as cursors
con = MySQLdb.connect(host = 'localhost', user = 'test', passwd = 'xx', 
                           db = 'yy', cursorclass = cursors.SSCursor)

这就是

SSCursor

的完整定义

除非您特别需要对BaseCursor进行不同的子类划分，否则您可以像这样使用

SSCursor

：

class SSCursor(CursorUseResultMixIn, CursorTupleRowsMixIn,
               BaseCursor):

    """This is a Cursor class that returns rows as tuples and stores
    the result set in the server."""

import MySQLdb.cursors as cursors
con = MySQLdb.connect(host = 'localhost', user = 'test', passwd = 'xx', 
                           db = 'yy', cursorclass = cursors.SSCursor)

另外还有一个

cursors.SSDictCursor

，它以字典的形式返回行，同时将结果集存储在服务器中

PPS。在Ubuntu 11.10上，

MySQLdb.cursors

模块通常位于

/usr/lib/pymodules/python2.7/MySQLdb/cursors.py