小编And*_*man的帖子

我有下表

CREATE TABLE actions (id INTEGER PRIMARY KEY, key1 NUMERIC, key2 NUMERIC);

我甚至不确定如何解释这个,所以我认为最好我举个例子:

id  key1 key2
1   1    1
2   1    2
3   1    1
4   2    1
5   2    3

输出这样的东西:

key1 key2 count(id)
1    1    2
1    2    1
2    1    1
2    3    1  

我试过这样的东西,但它不起作用,因为我需要key1字段不是唯一的:

Select  key1,key2,count(id)  from actions group by key2, order by key1

非常感谢

我在使用MySQLdb API时遇到了我认为是内存泄漏的问题

Line #    Mem usage    Increment   Line Contents
================================================
     6                             @profile
     7    10.102 MB     0.000 MB   def main():
     8    10.105 MB     0.004 MB       connection = MySQLdb.connect(host="localhost", db="mydb",
     9    11.285 MB     1.180 MB                                    user="notroot", passwd="Admin123", use_unicode=True)
    10    11.285 MB     0.000 MB       cursor = connection.cursor(cursorclass=MySQLdb.cursors.SSCursor)
    11                                 
    12    11.289 MB     0.004 MB       cursor.execute("select * from a big table;")
    13                                 
    14   254.078 MB   242.789 MB       results = [result for result in cursor]
    15   251.672 MB    -2.406 MB       del results
    16   251.672 MB     0.000 …