PDO：数据访问抽象层

时间：2022-03-11 02:29:03
<?php

//PDO：数据访问抽象层

//带有事务功能；

//dsn：数据源

$dsn="mysql:host=localhost;dbname=aaas";

//造pdo对象

$pdo=new PDO($dsn,"root","");//数据源，用户名，密码

//启动事务

$pdo->beginTransaction();

//写SQL语句

$sql="select * form Info";

//执行SQL语句

$a=$pdo->query($sql);

//回滚事务

//$pdo->RollBack();

foreach($a as $v)

{

    var_dump($v);

}

?>

<?php

　　特点二：

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">

<head>

    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />

    <title>下午</title>

</head>

<body>

<?php

//可以防止SQL注入攻击

$dsn="mysql:host=localhost;dbname=aaas";

$pdo=new PDO($dsn,"root","");

$sql="select * from Nation";

//将一条SQL语句放在服务器上准备运行

$stm=$pdo->prepare($sql);

//执行预处理语句,执行成功返回true，失败返回false

if($stm->execute())

{

    var_dump($stm->fetch());

}

?>

<?php

//可以防止SQL注入攻击

$dsn="mysql:host=localhost;dbname=aaas";

$pdo=new PDO($dsn,"root","");

$sql="insert into Nation values(?,?)";

//将一条SQL语句放在服务器上准备运行

$stm=$pdo->prepare($sql);

//绑定参数,数据较少的数据库,太复杂 不推荐

$stm->bindParam(1,$code);

$stm->bindParam(2,$name);

//给变量赋值

$code="n030";

$name="壮族";

//执行预处理语句,执行成功返回true，失败返回false

if($stm->execute());

{

    var_dump($stm->fetch());

}

?>

<?php

//可以防止SQL注入攻击

$dsn="mysql:host=localhost;dbname=aaas";

$pdo=new PDO($dsn,"root","");

$sql="insert into Nation values(?,?)";

//将一条SQL语句放在服务器上准备运行

$stm=$pdo->prepare($sql);

$attr=array("n005","苗族");

//执行预处理语句,执行成功返回true，失败返回false

if($stm->execute($attr));

{

}

?>

<?php

//可以防止SQL注入攻击

$dsn="mysql:host=localhost;dbname=aaas";

$pdo=new PDO($dsn,"root","");

$sql="insert into Nation values(:code,:name)";

//将一条SQL语句放在服务器上准备运行

$stm=$pdo->prepare($sql);

$attr=array("code"=>"n007","name"=>"水族");

//执行预处理语句,执行成功返回true，失败返回false

if($stm->execute($attr));

{

}

?>

</body>

</html>

　　

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