带有 MS SQL 的 Python - 截断的输出

Question

我尝试从 Linux box (Python 2.7、Ubuntu 11.04) 使用 python 连接到 MSSQL DB。我收到的输出被截断为 500 个字符。请参阅下面的脚本和配置。如何解决？我认为 ODBC 驱动程序或附近的问题。

代码(pyodbc、pymssql):

conn = pymssql.connect(host='my_remote_host', user='ro_user',
password='password', database='current', as_dict=True)
cur = conn.cursor()
cur.execute(sql)
for i in cur:
    print i
conn.close()

cnxn = pyodbc.connect(driver='FreeTDS', server='my_remote_host', database='current', uid='ro_user', pwd='password')
cursor = cnxn.cursor()
cursor.execute(sql)
rows = cursor.fetchall()
...
cnxn.close()  

我没有对 MS SQL DB 的写入权限，它实际上是不属于我们系统的远程服务器。

SQL:

sql = '''
        SELECT  Req.ID,
        ShReq.Summary AS [Short Name],
        ShReq.ALM_SharedText AS [Text],
        Req.ContainedBy,
        Req.DocumentID
FROM    CurMKS..ALM_Requirement Req
        JOIN CurMKS..ALM_SharedRequirement ShReq ON Req.[References] = ShReq.ID
        WHERE DocumentID = 1111111'''

问题出在 ShReq.ALM_SharedText 字段。它被截断为 255 个字符，但使用 convert(text,ShReq.ALM_SharedText) AS TEXT 和 CAST(ShReq.ALM_SharedText AS TEXT) 等转换我将截断增加到 500 个字符。但是，有些字段的文本长度超过 500 个字符，它们会被截断。

ODBC 设置:

/etc/odbc.ini:

[MKS]
#Driver=FreeTDS
Driver=/usr/lib/odbc/libtdsodbc.so
Description=Database
Trace=No
Server=my_remote_host
Port=1433
Database=current
UID=ro_user
PWD=password
TDS Version=8.0

/etc/odbcinst.ini:

[FreeTDS]
Description=FreeTDS
Driver=/usr/lib/odbc/libtdsodbc.so
UsageCount=1

/etc/freetds/freetds.conf:

[global]
        tds version = 8.0
;       dump file = /tmp/freetds.log
;       debug flags = 0xffff
;       timeout = 10
;       connect timeout = 10
;       text size = 2097152


[mksserver]
      host = my_remote_host
      port = 1433
      tds version = 8.0
      client charset = UTF-8

有什么想法可以解决吗？

Answer 1

将 freetds.conf 的 global 部分中的 text size 更改为最大(4294967295 字节):

[global]
    tds version = 8.0
    text size = 4294967295

还必须将 SQL 中的 TEXTSIZE 设置为最大值(2147483647 字节):

sql = """
    SET TEXTSIZE 2147483647;
    SELECT  Req.ID,
            ShReq.Summary AS [Short Name],
            ShReq.ALM_SharedText AS [Text],
            Req.ContainedBy,
            Req.DocumentID
    FROM    CurMKS..ALM_Requirement Req
            JOIN CurMKS..ALM_SharedRequirement ShReq ON Req.[References] = ShReq.ID
    WHERE DocumentID = 111111;
      """