php5.3的情况下，用pdo的dblib驱动无法连接mssql的，根据官方的描述，5.2已经修改这个bug，5.3没有。用php自带的mssql函数可以的
php5.3的情况下，用pdo的dblib驱动无法连接mssql的，，根据官方的描述，5.2已经修改这个bug，5.3没有。
用php自带的mssql函数可以的。编译freetds,php_mssql,pdo_dblib参数如下：
./configure --prefix=/usr/local/freetds --with-tdsver=8.0 --enable-msdblib
./configure --with-php-config=/usr/local/php/bin/php-config --with-mssql=/usr/local/freetds/
./configure --with-php-config=/usr/local/php/bin/php-config --with-mssql=/usr/local/freetds --enable-pdo --with-pdo-dblib=/usr/local/freetds/
用自带mssql函数无法设置字符集，set names 不被支持，最后参考了adodb的代码，发现解决这个问题还得用com，或者用ative mssql driver， 这两东西在windows下可以，linux还是不大好使的。解决办法是编辑/usr/local/freetds/etc/freetds.conf
加上一行client charset = GBK， 设置成utf-8是不对的，因为mssql排序规则数据库默认设置是Chinese PRC，相当于gb2312，
另外php.ini 里面mssql.charset 是不需要设置的，其实说得很清楚：
; Specify client character set.
; If empty or not set the client charset from freetds.comf is used
; This is only used when compiled with FreeTDS
当FreeTDS的client charset 为空或者没有设置的时候才需要设置这个。曾经错误的将这里设置成utf-8，FreeTDS的client charset 也设置成utf8，结果mssql_connect的时候就开始报错了。最终结论，只需要设置FreeTDS的client charset 为GBK，然后在php的程序里面iconv('GBK', 'UTF-8//IGNORE', $str);一下就一切正常了。
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