数据访问抽象层PDO

//数据访问抽象层PDO
//造DSN：驱动名：dbname=数据库名；host=服务器地址
$dsn = "mysql:dbname=mydb;host=localhost";
//造PDO对象
$pdo = new PDO($dsn,"root","xiao8888");
//写SQL语句
$sql = "select * from Info";
//执行SQL语句      //我们不这样执行，我们用预处理
//$v =$pdo->query($sql);
//返回的对象比较特殊，可以用循环遍历

//预处理：先把SQL语句放到服务器上等待我们给他指令去执行
//准备一条SQL语句
$stm = $pdo->prepare($sql);
//执行准备好的SQL语句
if($stm->execute())
{
    //1.逐行取数据
    var_dump($stm->fetch());    
    //2.取所有数据
    var_dump($stm->fetchAll());                  //包含关联数组与索引数组
    var_dump($stm->fetchAll(PDO::FETCH_ASSOC));  //返回关联数组
    var_dump($stm->fetchAll(PDO::FETCH_NUM));    //返回索引数组
    var_dump($stm->fetchAll(PDO::FETCH_OBJ));    //返回对象
    //3.取某一列
    var_dump($stm->fetchColumn(1));
    //4.返回对象
    var_dump($stm->fetchObject());
}
else
{
    echo "执行失败！";    
}

//造对象
$dsn = "mysql:dbname=mydb;host=localhost";
$pdo = new PDO($dsn,"root","xiao8888");
//写SQL语句，参数用？或者字符串代替
$sql= "insert into Nation vlaues(?,?)"; //问号绑定的是索引数组
$sql= "insert into Nation vlaues(:code,:name)";//字符串绑定的是关联数组

//预处理
$stm = $pdo->prepare($sql);

//给参数绑定值    太复杂，不推荐
$stm->bindParam(1,$code);//索引数组
$stm->bindParam(2,$name);

$stm->bindParam("code",$code,PDO::PARAM_STR);//关联数组
$stm->bindParam("name",$name,PDO::PARAM_STR);

$code = "p007";
$name = "回族";

//执行
if($stm->execute())
{
    echo "添加成功！";    
}
else
{
    echo "添加失败！";    
}

//造对象
$dsn = "mysql:dbname=mydb;host=localhost";
$pdo = new PDO($dsn,"root","xiao8888");
//写SQL语句，参数用？或者字符串代替
$sql= "insert into Nation vlaues(?,?)"; //问号绑定的是索引数组
$sql= "insert into Nation vlaues(:code,:name)";//字符串绑定的是关联数组
//预处理
$stm = $pdo->prepare($sql);
//造数组
$attr = array("n006","藏族");
$attr = array("code"=>"n006","name"=>"藏族");
//执行
if($stm->execute($attr))
{
    echo "添加成功！";    
}
else
{
    echo "添加失败！";    
}

<form action="Add.php" method="post">
<input type="text" name="code" />
<input type="text" name="name" />
<input type="submit" value="添加" />
</form>

<?php 
//造对象
$dsn = "mysql:dbname=mydb;host=localhost";
$pdo = new PDO($dsn,"root","xiao8888");
//写SQL语句
$sql = "insert into Nation values(:code,:name)";
//预处理
$stm = $pdo->prepare($sql);
//执行
if($stm->execute($_POST))
{
    echo "添加成功！";
}
else
{
    echo "添加失败！";    
}

<?php
class DB
{
    public $host="localhost";  //服务器地址     默认值为localhost
    public $uid="root";        //数据库用户名   默认值为root
    public $pwd="123";         //数据库密码     默认值为123

    /*数据访问抽象层PDO，可以从其他驱动访问数据库
    参数：
    $sql:  SQL语句
    $type: SQL语句类型，默认为0，代表查询语句，1代表其他语句
    $qdm:  驱动名，默认为mysql
    $db：  数据库名，默认为mydb*/
    
    public function QueryPDO($sql,$type=0,$qdm="mysql",$db="mydb")
    {
        //1.造DSN
        $dsn="$qdm:dbname=$db;host=$this->host";
        //2.造PDO对象
        $pdo=new PDO($dsn,$this->uid,$this->pwd);
        //3.预处理
        //准备一条SQL语句
        $stm =$pdo->prepare($sql);
        //执行SQL语句
        $stm->execute();
        if($type==0)
        { 
            return $stm->fetchAll();                
        }
        else
        {
            return $stm->execute();
        }            
    }
}