php mysql PDO 查询操作的实例详解

<?php 
$dbh = new PDO('mysql:host=localhost;dbname=access_control', 'root', '');  
$dbh->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);  
$dbh->exec('set names utf8');  
/*添加*/ 
//$sql = "INSERT INTO `user` SET `login`=:login AND `password`=:password";  
$sql = "INSERT INTO `user` (`login` ,`password`)VALUES (:login, :password)"; $stmt = $dbh->prepare($sql); $stmt->execute(array(':login'=>'kevin2',':password'=>''));  
echo $dbh->lastinsertid();  
/*修改*/ 
$sql = "UPDATE `user` SET `password`=:password WHERE `user_id`=:userId";  
$stmt = $dbh->prepare($sql);  
$stmt->execute(array(':userId'=>'7', ':password'=>'4607e782c4d86fd5364d7e4508bb10d9'));  
echo $stmt->rowCount();  
/*删除*/ 
$sql = "DELETE FROM `user` WHERE `login` LIKE 'kevin_'"; //kevin%  
$stmt = $dbh->prepare($sql);  
$stmt->execute();  
echo $stmt->rowCount();  
/*查询*/ 
$login = 'kevin%';  
$sql = "SELECT * FROM `user` WHERE `login` LIKE :login";  
$stmt = $dbh->prepare($sql);  
$stmt->execute(array(':login'=>$login));  
while($row = $stmt->fetch(PDO::FETCH_ASSOC)){    
 print_r($row);  
}  
print_r( $stmt->fetchAll(PDO::FETCH_ASSOC));  
?> 

<?php 
$dbh=newPDO('mysql:host=localhost;port=3306; dbname=test',$user,$pass,array( 
PDO::ATTR_PERSISTENT=>true 
)); 
?> 

<?php 
try{ 
$dbh=newPDO('mysql:host=localhost;dbname=test',$user,$pass); 
 
$dbh->setAttribute(PDO::ATTR_ERRMODE,PDO::ERRMODE_EXCEPTION); 
 
$dbh->exec("SET CHARACTER SET utf8"); 
$dbh=null; //断开连接 
}catch(PDOException$e){ 
print"Error!:".$e->getMessage()."<br/>"; 
die(); 
} 
?> 

<?php 
try{ 
$dbh->setAttribute(PDO::ATTR_ERRMODE,PDO::ERRMODE_EXCEPTION); 
 
$dbh->beginTransaction();//开启事务 
$dbh->exec("insertintostaff(id,first,last)values(23,'Joe','Bloggs')"); 
$dbh->exec("insertintosalarychange(id,amount,changedate) 
values(23,50000,NOW())"); 
$dbh->commit();//提交事务 
 
}catch(Exception$e){ 
$dbh->rollBack();//错误回滚 
echo"Failed:".$e->getMessage(); 
} 
?> 

$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

<?php 
try{   
 $dbh = new PDO($dsn, $user, $password);   
 $sql = 'Select * from city where CountryCode =:country';   
 $dbh->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_WARNING);   
 $stmt = $dbh->prepare($sql);   
 $stmt->bindParam(':country', $country, PDO::PARAM_STR);   
 $stmt->execute();   
 while ($row = $stmt->fetch(PDO::FETCH_ASSOC)) {    
 print $row['Name'] . "/t";   
 }  
}  // if there is a problem we can handle it here  
catch (PDOException $e) {   
 echo 'PDO Exception Caught. ';   
 echo 'Error with the database: <br />';   
 echo 'SQL Query: ', $sql;   
 echo 'Error: ' . $e->getMessage();  
}  
?> 

<?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";  
}  
?> 

<?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 
?> 

<?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();  
 }  
?>  

mixed pdostatement::fetch([int fetch_style [,int cursor_orientation [,int cursor_offset]]])
array pdostatement::fetchAll(int fetch_style)