EllisLab/CodeIgniter — pull request #1361 by appleboy (2012-05-16 06:02:45+00:00)
Title: odbc driver connections with MSSQL

When I use odbc driver for MSSQL, some error messages as below, but it is working for connecting to MySQL.

```code
[Microsoft][ODBC SQL Server Driver][SQL Server]Incorrect syntax near ')'.

SELECT * FROM (ci_sessions) WHERE session_id = '3ad914bb5f5728e8ac69ad1db8fc9841' AND user_agent = 'Mozilla/5.0 (Windows NT 6.1; rv:10.0.2) Gecko/20100101 Firefox/10.0.2'
```
I modified the _from_tables function of odbc driver to fix this issue.