PDO的基础学习操作--php线上班第九期

1. pdo操作：连接、增删查改操作(手写)

<?php
//pdo连接
//第一个参数是一个组合
//mysql:标识
//host=地址
//dbname=库名
//$pdo=new PDO('mysql:host:127.0.0.1;dbname=demo','root','root');
//print_r($pdo);
//数据库连接参数
$db =[
    'type'=>'mysql',
    'host'=>'localhost',
    'dbname'=>'demo',
    'username'=>'root',
    'password'=>'root',
    'part'=> 3306
];
$dsn ="{$db['type']}:host={$db['host']};dbname={$db['dbname']}";
//$pdo =new PDO($dsn,$db['username'],$db['password']);
//print_r($pdo);
//报错时常用
try{
    $pdo = new PDO($dsn,$db['username'],$db['password']);
}catch(PDOException $e){
    die($e->getMessage());
}

2. 练熟pdo操作

<?php
require __DIR__.'/demo1.php';
//尽可能把参数变成可变的值,所以可以让自己更变名称
//创建sql语句模板
$sql ='INSERT INTO `demo1`SET `id`=:i';
//预处理
$stmt = $pdo ->prepare($sql);
//stmt是什么？是预处理语句
//要绑定语句，需要对预处理语句的参数进行设定
$stmt ->bindParam('i',$id,PDO::PARAM_INT);
$add =$stmt ->execute();
 if($add){
     $count =$stmt -> rowCount();
     if($count>0){
         echo'数据插入成功';
     }else{
         echo '数据插入失败';
     }
 }else{
     die(print_r($stmt-> errorInfo(),ture));
 }
 $pdo = null;
 print_r($pdo);

<?php
require __DIR__.'/demo1.php';
$sql = 'UPDATE `demo1` SET `name`=:n,`id`=:i
        WHERE `state`=:s';
$stmt = $pdo ->prepare($sql);
 $name='外公司';
 $id='3';
 $state='0';
 $stmt->bindParam('n',$name,PDO::PARAM_STR);
 $stmt->bindParam('i',$id,PDO::PARAM_STR);
$stmt->bindParam('s',$state,PDO::PARAM_STR);
 $add = $stmt->execute();
if($add){
    $count = $stmt-> rowCount();
    if($count>0){
        echo '数据插入成功';
    }else{
        echo'插入失败';
    }
}else{
    die(print_r($stmt-> errorinfo(),true));
}

<?php
require __DIR__.'/demo1.php';
$sql ='SELECT * FROM `demo1`';
$stmt =$pdo -> prepare($sql);
$add= $stmt ->execute();
if ($add){
    print_r($stmt->fetchAll());
}else{
    die(print_r($stmt-> errorInfo(),true));
}