使用ODBC方式读取sybase数据库的时候，如果字符串大于4k(4096),结果只能读取到4096个字符（关键字 SYBASE TEXT 4096 截断 TRUNCATE）

没搞过sybase ,这次搞sybase遇到这种很难在中午网上找到答案的问题，最终还是向英文网站求助

O(∩_∩)O哈哈~

 

总结解决方案：

Check these steps out - there is a new attribute to handle the Buffer column
size, not available in the
GUI configuration (I tried to get this in there!) and not sure why it can't be
there. The problem occurred at the
older 3.50 level when the driver started supporting Static cursors. Check these
items below and it should be OK ...

1. Check the TEXTSIZE for the ASE. On 12.5 it defaults to 32768 bytes. You
need this set to the anticipated
maximum text/image size.

2. The DSN itself has 2 options for this limitation. "DefaultLongDataBuffLen"
or Default Buffer Size for Long
Columns defaults to 1024 KBs (or 1 MB).

3. The StaticCursorLongColBuffLen was introduced to the 3.50 CtLib based driver
(12.0) for when the application
uses cursors. It is not accessible via the configuration screens and must be
added to the registry under the
DSN being used. This option defaults to 4096 Bytes (4K). You need to add this
in your connection string
(StaticCursorLongColBuffLen (SCLCBL - I think)) in BYTEs.（我就用的这个方案解决了问题）

These options have limitations because the driver pre-allocates these buffers
whenever the TEXT or IMAGE
datatype is to be used in your stmt.

On ASE whenever the text/image size is limited, silent truncation usually
occurs. This is behavior
on the ASE not the client.

I suggest you setup the 2 buffer length parameters in anticipation of the
maximim size of the BLOB type. The pre-allocation occurs
during the runtime, not when the driver itself is initialized.

实际操作：

在HKEY_LOCAL_MACHINE\SOFTWARE\ODBC\ODBC.INI\<ODBC 的dsn名称>注册表下，添加StaticCursorLongColBuffLen值为40960

当然这个值不一定要40960，只要大于4096就可以了哦

 

北大方正数字媒体部门陈炼

 

2013年10月17日14:24:17