Question

我想序列化查询结果。这是我的例子：

_pickle.PicklingError: Can't pickle <class 'pypyodbc.TupleRow.<locals>.Row'>: 
attribute lookup Row on pypyodbc failed

它会产生以下错误：

select state
from customers
group by state
having count(*) = (select min(cnt)
                   from (select count(*) from customers group by state) s
                  );

我认为pickle并不完全支持pypyodbc对象。什么是解决方法？

Answer 1

我能够使用pypyodbc重新创建问题，而相同的代码似乎可以与pyodbc一起使用。 pypyodbc的一种可能的解决方法可能是将结果转换为字典对象列表，然后序列化：

import pickle, pypyodbc
connection_string = (
    r"Driver={SQL Server Native Client 10.0};"
    r"Server=(local)\SQLEXPRESS;"
    r"Database=myDb;"
    r"Trusted_connection=yes;"
)
connection = pypyodbc.connect(connection_string)
cur = connection.cursor()
cur.execute("SELECT * FROM Donors")

column_names = [x[0] for x in cur.description]
query_list = [dict(zip(column_names, row)) for row in cur.fetchall()]

with open(r'C:\Users\Gord\Desktop\query_result', 'wb') as f:
    pickle.dump(query_list, f)
cur.close()
connection.close()

泡菜和pypyodbc游标

1 个答案: