Here is how to get PHP 5.2 on Linux (specifically Debian/Ubuntu) talking to a Microsoft SQL Server database:

1. Install FreeTDS and the PHP MS SQL extension
$ sudo apt-get install freetds-common freetds-bin unixodbc php5-sybase

Note: That is correct, the MS SQL extension is in the “php5-sybase” package.

2. Restart Apache
$ sudo /etc/init.d/apache2 restart

3. Test FreeTDS
$ tsql -H your.server.name -p 1433 -U yourusername -P yourpassword -D yourdatabasename

If it connects, it’s working. Note: If you try to SELECT an NTEXT or NVARCHAR column you may get an error saying “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”. That is expected and will be fixed in the next step.

4. Configure FreeTDS
$ sudo vim /etc/freetds/freetds.conf

Add this at the end of the file:
[yourserver]
host = your.server.name
port = 1433
tds version = 8.0


5. Test FreeTDS using server name
$ tsql -S yourserver -U yourusername -P yourpassword -D yourdatabasename

If you try to select something, you shouldn’t get the Unicode error now – because you specified “tds version = 8.0”.

6. Test in PHP
$link = mssql_connect('yourserver', 'yourusername', 'yourpassword');
if (!$link)
die('Unable to connect!');
if (!mssql_select_db('yourdatabasename', $link))
die('Unable to select database!');
$result = mssql_query('SELECT * FROM yourtable');
while ($row = mssql_fetch_array($result)) {
var_dump($row);
}
mssql_free_result($result);


Source link: https://davejamesmiller.com/blog/connecting-php-to-microsoft-sql-server-...
T-SQL manual page: https://linux.die.net/man/1/tsql