php mysql PDO使用

$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) );

mysql常用：http://blog.csdn.net/yjj1s/archive/2011/05/23/6440345.aspx

1 建立连接

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

持久性链接PDO::ATTR_PERSISTENT=>true

2. 捕捉错误

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();
}

3. 事务的

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();
}

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

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(); }

==========================

1. 使用 query()

$dbh->query($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]

$dbh->prepare($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，

pdo mysql dsn(Data Source Name)http://www.php.net/manual/zh/ref.pdo-mysql.connection.php

参考：http://hi.baidu.com/traindiy/blog/item/050f3087a544e621c75cc378.html

http://www.php.net/manual/zh/book.pdo.php

• PDO— The PDO class
  • PDO::beginTransaction— Initiates a transaction
  • PDO::commit— Commits a transaction
  • PDO::__construct— Creates a PDO instance representing a connection to a database
  • PDO::errorCode— Fetch the SQLSTATE associated with the last operation on the database handle
  • PDO::errorInfo— Fetch extended error information associated with the last operation on the database handle
  • PDO::exec— Execute an SQL statement and return the number of affected rows
  • PDO::getAttribute— Retrieve a database connection attribute
  • PDO::getAvailableDrivers— Return an array of available PDO drivers
  • PDO::inTransaction— Checks if inside a transaction
  • PDO::lastInsertId— Returns the ID of the last inserted row or sequence value
  • PDO::prepare— Prepares a statement for execution and returns a statement object
  • PDO::query— Executes an SQL statement, returning a result set as a PDOStatement object
  • PDO::quote— Quotes a string for use in a query.
  • PDO::rollBack— Rolls back a transaction
  • PDO::setAttribute— Set an attribute
• PDOStatement— The PDOStatement class
  • PDOStatement->bindColumn— Bind a column to a PHP variable
  • PDOStatement->bindParam— Binds a parameter to the specified variable name
  • PDOStatement->bindValue— Binds a value to a parameter
  • PDOStatement->closeCursor— Closes the cursor, enabling the statement to be executed again.
  • PDOStatement->columnCount— Returns the number of columns in the result set
  • PDOStatement->debugDumpParams— Dump an SQL prepared command
  • PDOStatement->errorCode— Fetch the SQLSTATE associated with the last operation on the statement handle
  • PDOStatement->errorInfo— Fetch extended error information associated with the last operation on the statement handle
  • PDOStatement->execute— Executes a prepared statement
  • PDOStatement->fetch— Fetches the next row from a result set
  • PDOStatement->fetchAll— Returns an array containing all of the result set rows
  • PDOStatement->fetchColumn— Returns a single column from the next row of a result set
  • PDOStatement->fetchObject— Fetches the next row and returns it as an object.
  • PDOStatement->getAttribute— Retrieve a statement attribute
  • PDOStatement->getColumnMeta— Returns metadata for a column in a result set
  • PDOStatement->nextRowset— Advances to the next rowset in a multi-rowset statement handle
  • PDOStatement->rowCount— Returns the number of rows affected by the last SQL statement
  • PDOStatement->setAttribute— Set a statement attribute
  • PDOStatement->setFetchMode— Set the default fetch mode for this statement