1 <?php 2 $dbh = new PDO('mysql:host=localhost;dbname=access_control', 'root', '');   3 $dbh->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);   4 $dbh->exec('set names utf8');  5 /*添加*/ 6 //$sql = "INSERT INTO `user` SET `login`=:login AND `passWord`=:password";  7 $sql = "INSERT INTO `user` (`login` ,`password`)VALUES (:login, :password)";  $stmt = $dbh->PRepare($sql);  $stmt->execute(array(':login'=>'kevin2',':password'=>''));   8 echo $dbh->lastinsertid();   9 /*修改*/10 $sql = "UPDATE `user` SET `password`=:password WHERE `user_id`=:userId";  11 $stmt = $dbh->prepare($sql);  12 $stmt->execute(array(':userId'=>'7', ':password'=>'4607e782c4d86fd5364d7e4508bb10d9'));  13 echo $stmt->rowCount(); 14 /*删除*/15 $sql = "DELETE FROM `user` WHERE `login` LIKE 'kevin_'"; //kevin%  16 $stmt = $dbh->prepare($sql);  17 $stmt->execute();  18 echo $stmt->rowCount();  19 /*查询*/20 $login = 'kevin%';  21 $sql = "SELECT * FROM `user` WHERE `login` LIKE :login";  22 $stmt = $dbh->prepare($sql);  23 $stmt->execute(array(':login'=>$login));  24 while($row = $stmt->fetch(PDO::FETCH_ASSOC)){     25  print_r($row);  26 }  27 print_r( $stmt->fetchAll(PDO::FETCH_ASSOC)); 28 ?>

1 建立连接

1 <?php2 $dbh=newPDO('mysql:host=localhost;port=3306; dbname=test',$user,$pass,array(3 PDO::ATTR_PERSISTENT=>true4 ));5 ?>

持久性链接PDO::ATTR_PERSISTENT=>true

2. 捕捉错误

 1 <?php 2 try{ 3 $dbh=newPDO('mysql:host=localhost;dbname=test',$user,$pass); 4  5 $dbh->setAttribute(PDO::ATTR_ERRMODE,PDO::ERRMODE_EXCEPTION); 6  7 $dbh->exec("SET CHARACTER SET utf8"); 8 $dbh=null; //断开连接 9 }catch(PDOException$e){10 print"Error!:".$e->getMessage()."<br/>";11 die();12 }13 ?>

3. 事务的

 1 <?php 2 try{ 3 $dbh->setAttribute(PDO::ATTR_ERRMODE,PDO::ERRMODE_EXCEPTION); 4  5 $dbh->beginTransaction();//开启事务 6 $dbh->exec("insertintostaff(id,first,last)values(23,'Joe','Bloggs')"); 7 $dbh->exec("insertintosalarychange(id,amount,changedate) 8 values(23,50000,NOW())"); 9 $dbh->commit();//提交事务10 11 }catch(Exception$e){12 $dbh->rollBack();//错误回滚13 echo"Failed:".$e->getMessage();14 }15 ?>

4. 错误处理

a. 静默模式(默认模式)

$dbh->setAttribute(PDO::ATTR_ERRMODE,PDO::ERRMODE_SILENT); //不显示错误

$dbh->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_WARNING);//显示警告错误，并继续执行

$dbh->setAttribute(PDO::ATTR_ERRMODE,PDO::ERRMODE_EXCEPTION);//产生致命错误，PDOException

 1 <?php 2 try{     3  $dbh = new PDO($dsn, $user, $password);     4  $sql = 'Select * from city where CountryCode =:country';     5  $dbh->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_WARNING);     6  $stmt = $dbh->prepare($sql);     7  $stmt->bindParam(':country', $country, PDO::PARAM_STR);     8  $stmt->execute();     9  while ($row = $stmt->fetch(PDO::FETCH_ASSOC)) {      10   print $row['Name'] . "/t";    11  }  12 }   // if there is a problem we can handle it here  13 catch (PDOException $e)  {    14  echo 'PDO Exception Caught.  ';    15  echo 'Error with the database: <br />';    16  echo 'SQL Query: ', $sql;   17  echo 'Error: ' . $e->getMessage();  18 } 19 ?>

1. 使用 query()

<?php$dbh->query($sql); 当$sql 中变量可以用$dbh->quote($params); //转义字符串的数据$sql = 'Select * from city where CountryCode ='.$dbh->quote($country);  foreach ($dbh->query($sql) as $row)   {     print $row['Name'] . "/t";     print $row['CountryCode'] . "/t";     print $row['Population'] . "/n"; } ?>

2. 使用 prepare, bindParam和 execute [建议用,同时可以用添加、修改、删除]

<?php$dbh->prepare($sql); 产生了个PDOStatement对象PDOStatement->bindParam()PDOStatement->execute();//可以在这里放绑定的相应变量?>

3. 事物

<?php  try {    $dbh = new PDO('mysql:host=localhost;dbname=test', 'root', '');    $dbh->query('set names utf8;');    $dbh->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);    $dbh->beginTransaction();    $dbh->exec("Insert INTO `test`.`table` (`name` ,`age`)VALUES ('mick', 22);");    $dbh->exec("Insert INTO `test`.`table` (`name` ,`age`)VALUES ('lily', 29);");   $dbh->exec("Insert INTO `test`.`table` (`name` ,`age`)VALUES ('susan', 21);");    $dbh->commit();  } catch (Exception $e) {    $dbh->rollBack();    echo "Failed: " . $e->getMessage();   }  ?> 

PDO常用方法：PDO::query()主要用于有记录结果返回的操作（PDOStatement），特别是select操作。

PDO::exec()主要是针对没有结果集合返回的操作。如insert,update等操作。返回影响行数。PDO::lastInsertId()返回上次插入操作最后一条ID，但要注意：如果用insert into tb(col1,col2) values(v1,v2),(v11,v22)..的方式一次插入多条记录，lastinsertid()返回的只是第一条(v1,v2)插入时的ID,而不是最后一条记录插入的记录ID。PDOStatement::fetch()是用来获取一条记录。配合while来遍历。PDOStatement::fetchAll()是获取所有记录集到一个中。PDOStatement::fetchcolumn([int column_indexnum])用于直接访问列，参数column_indexnum是该列在行中的从0开始索引值，但是，这个方法一次只能取得同一行的一列，只要执行一次，就跳到下一行。因此，用于直接访问某一列时较好用，但要遍历多列就用不上。PDOStatement::rowcount()适用于当用query("select ...")方法时，获取记录的条数。也可以用于预处理中。$stmt->rowcount();PDOStatement::columncount()适用于当用query("select ...")方法时，获取记录的列数。

注解：1、选fetch还是fetchall？小记录集时，用fetchall效率高，减少从数据库检索次数，但对于大结果集，用fetchall则给系统带来很大负担。数据库要向WEB前端传输量太大反而效率低。2、fetch()或fetchall()有几个参数：mixed pdostatement::fetch([int fetch_style [,int cursor_orientation [,int cursor_offset]]])array pdostatement::fetchAll(int fetch_style)

fetch_style参数:■$row=$rs->fetchAll(PDO::FETCH_BOTH); FETCH_BOTH是默认的，可省，返回关联和索引。■$row=$rs->fetchAll(PDO::FETCH_ASSOC); FETCH_ASSOC参数决定返回的只有关联数组。■$row=$rs->fetchAll(PDO::FETCH_NUM); 返回索引数组■$row=$rs->fetchAll(PDO::FETCH_OBJ); 如果fetch()则返回对象，如果是fetchall(),返回由对象组成的二维数组