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)