Connect to the MySQL database using PDO

<?php//Use PDO to connect to MySQL databaseClass pdo_con{var $dsn = ' mysql:dbname=test; host:127.0.0.1 '; var $user = ' root ';    var $password = ';    var $opt = array (pdo::attr_persistent=>true);    var $dbh; function __construct () {try{$this->dbh = new PDO ($this->dsn, $this->user, $this->password, $th IS-&GT;OPT); Object-oriented construction method pass value this//var_dump ($DBH);d ie ();
}catch (pdoexception $e) {echo ' Database connection failed: '. $e->getmessage ();        Exit }    }

$rs = $dbh->query (' select * from user '),//Var_dump ($pdostatement->rowcount ());d ie (); Var_dump ($RS);

echo "\npdo Turn off autocommit feature:". $DBH->getattribute (Pdo::attr_autocommit);    echo "\ n current PDO's error handling mode:". $DBH->getattribute (Pdo::attr_errmode);    echo "\ n case conversion of table field characters:". $dbh->getattribute (pdo::attr_case);    echo "\ n specific information related to connection status:". $DBH->getattribute (pdo::attr_connection_status);    echo "\ n empty string converted to SQL null:". $DBH->getattribute (pdo::attr_oracle_nulls);    echo "\ n the application gets the data size in advance:". $DBH->getattribute (pdo::attr_persistent);    echo "\ n database-specific server information:". $DBH->getattribute (Pdo::attr_server_info);    echo "\ nthe database server version information:". $DBH->getattribute (pdo::attr_server_version);    echo "\ n Database client version number information:". $DBH->getattribute (pdo::attr_client_version);    echo "\ n setting throws exception handling error:". $DBH->setattribute (pdo::attr_errmode,pdo::errmode_exception); echo "\ n Sets the empty string to null:". $DBH->setattribute (pdo::attr_oracle_nulls,true);

function Select ($table, $where = ', $order = ', $limits = ', $field = ') {$where = ($where ==null)? ': ' Where '. $where;        $order = ($order ==null)? ': ' Order by '. $order;        $limits = ($limits ==null)? ': ' Limit '. $limits; $field = ($field ==null)? '        * ': $field; $sele = ' SELECT '. $field. '        From '. $table. $where. $order. $limits. '; ';        $kk = $this->dbh->query ($sele); $kk->setfetchmode (PDO::FETCH_ASSOC);    Set fetch to return $KK after the query statement; }

}
$ss =new Pdo_con ();//Var_dump ($SS);            $rs = $ss->select (' user ');            foreach ($rs as $value) {# code ... var_dump ($value);            echo $value [' username ']; Echo ' <br> ';}

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Connect to the MySQL database using PDO