我在Debian Lenny（5.0.7）上成功使用pyodbc时遇到了一些问题。特别是，我似乎在获取NVARCHAR值时遇到了问题（不是SQL Server专家，所以请放心：）。
大多数传统查询都可以正常工作。例如，表1中的行数产生
cursor.execute("SELECT count(id) from table1")
<pyodbc.Cursor object at 0xb7b9b170>
>>> cursor.fetchall()
[(27, )]
像完整转储的ids 一样
>>> cursor.execute("SELECT id FROM table1")
<pyodbc.Cursor object at 0xb7b9b170>
>>> cursor.fetchall()
[(0.0, ), (3.0, ), (4.0, ), (5.0, ), (6.0, ), (7.0, ), (8.0, ), (11.0, ), (12.0, ), (18.0, ), (19.0, ), (20.0, ), (21.0, ), (22.0, ), (23.0, ), (24.0, ), (25.0, ), (26.0, ), (27.0, ), (28.0, ), (29.0, ), (32.0, ), (33.0, ), (34.0, ), (35.0, ), (36.0, ), (37.0, )]
但是名称转储（同样是NVARCHAR类型）并不能
>>> cursor.execute("SELECT name FROM table1")
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
pyodbc.ProgrammingError: ('42000', '[42000] [FreeTDS][SQL Server]Unicode data in a Unicode-only collation or ntext data cannot be sent to clients using DB-Library (such as ISQL) or ODBC version 3.7 or earlier. (4004) (SQLExecDirectW)')
关键错误是
pyodbc.ProgramingError:（'42000'，'[42000][FreeTDS][SQL Server]仅使用Unicode排序规则的Unicode数据或ntext数据无法使用DB-Library（如ISQL）或ODBC 3.7或更早版本发送到客户端。（4004）（SQLExecDirectW）'）
这在各表中是一致的。
我已经尝试了每种版本的各种不同版本，但现在我运行的是unixODBC 2.2.11（来自lenny repos）、FreeTDS 0.91（从源代码构建，带有./configure --enable-msdblib --with-tdsver=8.0）和pyodbc 3.0.3（从源程序构建）。
使用类似的组合（unixODBC 2.3.0、FreeTDS 0.91、pyodbc 3.0.3），相同的代码适用于Mac OS X 10.7.2。
我到处搜索，研究这里和这里提供的解决方案，并重新编译不同版本的unixODBC和FreeTDS，但仍然没有骰子。提供的相关配置文件如下：
user@host:~$ cat /usr/local/etc/freetds.conf
#$Id: freetds.conf,v 1.12 2007/12/25 06:02:36 jklowden Exp $
#
# This file is installed by FreeTDS if no file by the same
# name is found in the installation directory.
#
# For information about the layout of this file and its settings,
# see the freetds.conf manpage "man freetds.conf".
# Global settings are overridden by those in a database
# server specific section
[global]
# TDS protocol version
tds version = 8.0
client charset = UTF-8
# Whether to write a TDSDUMP file for diagnostic purposes
# (setting this to /tmp is insecure on a multi-user system)
; dump file = /tmp/freetds.log
; debug flags = 0xffff
# Command and connection timeouts
; timeout = 10
; connect timeout = 10
# If you get out-of-memory errors, it may mean that your client
# is trying to allocate a huge buffer for a TEXT field.
# Try setting 'text size' to a more reasonable limit
text size = 64512
# A typical Sybase server
[egServer50]
host = symachine.domain.com
port = 5000
tds version = 5.0
# A typical Microsoft server
[egServer70]
host = ntmachine.domain.com
port = 1433
tds version = 8.0
[foo]
host = foo.bar.com
port = 1433
tds version = 8.0
user@host:~$ cat /etc/odbc.ini
[foo]
Description = Foo
Driver = foobar
Trace = No
Database = db
Server = foo.bar.com
Port = 1433
TDS_Version = 8.0
user@host:~$ cat /etc/odbcinst.ini
[foobar]
Description = Description
Driver = /usr/lib/odbc/libtdsodbc.so
Setup = /usr/lib/odbc/libtdsS.so
CPTimeout =
CPReuse =
如有任何建议或指示，我们将不胜感激！
我在Ubuntu中遇到了同样的错误。我用变通办法"解决"了这个问题。您所需要做的就是设置环境变量TDSVER。
import os
os.environ['TDSVER'] = '8.0'
正如我所说，这不是一个真正的"解决方案"，但它是有效的。
尝试添加
TDS_Version=8.0;ClientCharset=UTF-8
在您的连接字符串中。
例如，
DRIVER=FreeTDS;SERVER=myserver;DATABASE=mydatebase;UID=me;PWD=pwd;TDS_Version=8.0;ClientCharset=UTF-8
是否可以绕过问题，将name转换或强制转换为它可以处理的内容？
cursor.execute（"SELECT CAST（name AS TEXT）FROM table"）