php连接不同数据库的几种方法

$conn = new Com("ADODB.Connection");     //实例化一个Connection对象
$connstr = "provider=sqloledb;datasource=.;uid=sa;pwd=123456;database=jnold;";
$conn->Open($connstr);
$rs = new Com("ADODB.Recordset");    //实例化一个Recordcount对象

$rs->Open('select * from News where bigclassid = 59 And LeadPostil is null', $conn, 1, 1);
$count = $rs->RecordCount;
echo "共有{$count}条纪录<br />";
for($i = 0; $i < $count ; $i++){
     $arr_result[$i]['Title'] = addslashes($rs->Fields('Title')->Value);//标题
     $arr_result[$i]['Color'] = addslashes($rs->Fields('titlecolor')->Value?$rs->Fields('titlecolor')->Value:'');//标题颜色
     $arr_result[$i]['WenHao'] = addslashes($rs->Fields('OtherText')->Value);//文号
}

$dbhost = '';
$dbuser = ''; //你的mssql用户名
$dbpass = ''; //你的mssql密码
$dbname = ''; //你的mssql库名

$connect=odbc_connect("Driver={SQL Server};Server=$dbhost;Database=$dbname","$dbuser","$dbpass");
$sql="select * from content";
$exec=odbc_exec($connect,$sql);
while($row = (odbc_fetch_array($exec)))
{
$row['id']   //獲取字段值
...
}

<?
$dbh=mssql_connect("192.168.12.124","sa","");
mssql_select_db("mydb", $dbh);
?>
 

$db=$_SERVER['DOCUMENT_ROOT']."/PHP_ACCESS/include/#mydb.mdb";    //這裏最好用$_SERVER['DOCUMENT_ROOT']獲取路徑
$conn = new COM('ADODB.Connection') or die('can not start Active X Data Objects');
$conn->Open("DRIVER={Microsoft Access Driver (*.mdb)}; DBQ=$db");
      $rs = $conn->Execute('SELECT * FROM contents order by id desc');
      while(!$rs->EOF) 
             {
               echo $rs->Fields['name']->Value;
               $rs->MoveNext();
      }
    /*释放资源*/
    $rs->Close();
       $conn->Close();
       $rs = null;
       $conn = null;

$database_connection=null;

 $hostname="localhost";
 $database="5aart";
 $username="root";
 $password="1234";
 global $database_connection;
 $database_connection=mysql_connect($hostname,$username,$password) or die(mysql_error());
 mysql_query("set names 'gbk'");
 mysql_select_db($database,$database_connection) or die(mysql_error());

$dbhost = 'localhost';
$dbuser = 'sa'; //你的mssql用户名
$dbpass = '1234'; //你的mssql密码
$dbname = '0772fang'; //你的mssql库名
$connect=odbc_connect("Driver={SQL Server};Server=$dbhost;Database=$dbname","$dbuser","$dbpass");
$sql="update news_pk set ffnums=ffnums+1 where newsID='$ID'";
$exec=odbc_exec($connect,$sql);