Database Abstraction Layer PDO

I. Connection of PDO

$host= "localhost"; $dbname= "Hejuntest"; $username= "Root"; $pwd= ""; $dsn= "mysql:host=$host;d bname=$dbname"; $opt=Array(Pdo::attr_persistent =TRUE);//Persistent Links    Try{        $pdo=NewPDO ($dsn,$username,$pwd,$opt); }Catch(pdoexception$e){        Echo' Connect error~ '.$e-Get_message (); }

Second, the increase, deletion and modification of PDO

    $sql = "Update student set name= ' Xiaoran ' where ID in (");     $affted _rows $pdo,exec($sql);  // returns the number of rows affected

Third, the search for PDO

• Use Fetch ()

    $sql= "SELECT * FROM Student"; $pdostatement=$pdo->query ($sql); Echo' <table> ';  while(List($id,$name,$age,$class) =$pdostatement->fetch (PDO::fetch_num)) {        Echo' <tr> '; Echo' <td> '.$id.‘ </td> '; Echo' <td> '.$name.‘ </td> '; Echo' <td> '.$age.‘ </td> '; Echo' <td> '.$class.‘ </td> '; Echo' </tr> '; }    Echo' </table> ';

• Using Fetchall ()

$sql= "SELECT * FROM Student"; $pdostatement=$pdo->query ($sql); $data=$pdostatement->fetchall (PDO::FETCH_ASSOC); Echo' <table> '; foreach($data  as $k=$v){        Echo' <tr> '; Echo' <td> '.$v[' ID ']. ' </td> '; Echo' <td> '.$v[' name ']. ' </td> '; Echo' <td> '.$v[' Age ']. ' </td> '; Echo' <td> '.$v[' class ']. ' </td> '; Echo' </tr> '; }    Echo' </table> ';

Iv. pretreatment of PDO (Pretreatment is supported)

• Specifying a moniker Binding variable

$sql= "INSERT into student (Name,age,class) VALUES (: Name,:age,:class)"; $pdostatement=$pdo->prepare ($sql); $pdostatement->bindparam (": Name",$name); $pdostatement->bindparam (": Age",$age); $pdostatement->bindparam (": Class",$class); $name= "Hejun"; $age= 25; $class= 15; $pdostatement-execute (); $name= "Daxi"; $age= 26; $class= 16; $pdostatement->execute ();

• ? Symbolic binding variables

$sql= "INSERT into student (Name,age,class) VALUES (?,?,?)"; $pdostatement=$pdo->prepare ($sql); $pdostatement->bindparam (1,$name); $pdostatement->bindparam (2,$age); $pdostatement->bindparam (3,$class); $name= "Hejun"; $age= 25; $class= 15; $pdostatement-execute (); $name= "Daxi"; $age= 26; $class= 16; $pdostatement->execute ();

• Omit bound variable method

    $sql = "INSERT into student (Name,age,class) VALUES (?,?,?)" ;     $pdostatement $pdo->prepare ($sql);     $pdostatement->execute (array("Daxixi", 20,11));     Echo $pdo // If there is a primary key, get the last inserted primary key value    Echo $pdostatement->rowcount (); // get the number of affected rows

Database Abstraction Layer PDO