PHP4 PDO

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【pdo】开始

PDO --- PHP 数据对象

PHP专门用来连接数据库的东西，通过一套函数连接不同的数据库

在你是用之前开启PDO模块

开启：

在咱们的php.ini 里面extension=php_pdo_mysql.dll注释打开

mysqli数据库链接方式

1、链接数据库

2、判断是否成功

3、设置字符集

4、选择数据库

5、准备sql语句

6、发送

7、处理结果集

8、数据库链接关闭

$dsn = 'mysql:host=localhost;dbname=blog;charset=utf8';

$pdo->query(set names utf8);

【数据库引擎】

myisam

不支持事务

innodb

支持事务

【关于pdo的事务】

$pdo->beginTransaction();

$pdo->exec($sql);

$pdo->rollBack();

$pdo->commit();

<?php

try {
    $dsn = 'mysql:host=localhost;dbname=blog;charset=utf8';
    $pdo = new PDO($dsn , 'root' , 'kungezuishuai');
    $sql = "update money set amoney=money-1000 where id = 1";
    $pdo->setAttribute(PDO::ATTR_ERRMODE,PDO::ERRMODE_WARNING);

    echo $pdo->errorCode();
    $arr = $pdo->errorInfo();
    var_dump($arr);
    /*
    $pdo->beginTransaction();
    $result = $pdo->exec($sql);
    //$pdo->rollBack();
    $pdo->commit();
    */
} catch(PDOException $e) {
    echo '我遇到了一些异常<br />';
    echo $e->getMessage().'<br />';
    echo $e->getCode().'<br />';
}

获取最后一条插入的自增id

$pdo->lastInsertId();

<?php

try {
    $dsn = 'mysql:host=localhost;dbname=blog;charset=utf8';
    $pdo = new PDO($dsn , 'root' , 'kungezuishuai');
    $sql = "insert into money(username , money) values('张三' , 200)";
    $result = $pdo->exec($sql);
    echo $pdo->lastInsertId();

} catch (PDOException $e) {
    $e->getCode();
}

预处理——添加

<?php
try {
    $dsn = 'mysql:host=localhost;dbname=blog;charset=utf8';
    $pdo = new PDO($dsn , 'root' , 'kungezuishuai');

    //接下来重点 预处理
    //第一种方法
    /*$stmt = $pdo->prepare('insert into money(username , money) values(? , ?)');
    $stmt->bindValue(1 , '没劲');
    $stmt->bindValue(2 , 3000);
    $result = $stmt->execute();*/
    //第二种方法
    $stmt = $pdo->prepare('insert into money(username , money) values(:username , :money)');
    $username = '不好好学习，就是***';
    $money = 30000;

    $stmt->bindParam(':username' , $username);
    $stmt->bindParam(':money' , $money);
    //$stmt->execute([':username' => '我是李坤' , ':money' => 200000000]);//这样插入也可
    $result = $stmt->execute();
    if ($result) {
         echo 'success';
    } else {
        echo 'failed';
    }

} catch (PDOException $e) {
    echo $e->getCode();
}

预处理——修改

<?php

try {

    $dsn = 'mysql:host=localhost;dbname=blog;charset=utf8';
    $pdo = new PDO($dsn , 'root' , 'kungezuishuai');

    $stmt = $pdo->prepare('update money  set username=? where id=?');
    $stmt->execute(['小甜瓜' , 4]);

} catch (PDOException $e) {

}

预处理——删除

<?php
try {

    $dsn = 'mysql:host=localhost;dbname=blog;charset=utf8';
    $pdo = new PDO($dsn , 'root' , 'kungezuishuai');

    /*
    $stmt = $pdo->prepare('delete from money where id = :id');
    $stmt->execute(['id' => 1]);
    */

    $del = $pdo->prepare('DELETE FROM money');
    $del->execute();

    $count = $del->rowCount();

    var_dump($count);

} catch (PDOException $e) {

}

预处理——查询1

<?php
$dsn = 'mysql:host=localhost;dbname=blog;charset=utf8';
$pdo = new PDO($dsn , 'root' , 'kungezuishuai');

$stmt = $pdo->prepare('select * from money where id>:id');
$stmt->execute(['id' => 1]);

while ($row = $stmt->fetch(PDO::FETCH_ASSOC)) {
    echo $row['id'].'----'.$row['username'].'---'.$row['money'].'<br/>';
}

预处理——查询2

<?php

try{
    $dsn = 'mysql:host=localhost;dbname=blog;charset=utf8';
    $pdo = new PDO($dsn , 'root' , 'kungezuishuai');

    $stmt = $pdo->prepare('select id,username,money from money');

    $stmt->bindColumn(1 , $id);
    $stmt->bindColumn(2 , $username);
    $stmt->bindColumn(3 , $money);

    $stmt->execute();

    while ($stmt->fetch(PDO::FETCH_BOUND)) {
        echo $id.'<br />';
        echo $username.'<br />';
        echo $money.'<br />';
    }

} catch (PDOException $e) {

}

预处理——查询3

<?php

try{
    $dsn = 'mysql:host=localhost;dbname=blog;charset=utf8';
    $pdo = new PDO($dsn , 'root' , 'kungezuishuai');

    $stmt = $pdo->query('select * from money');

    $stmt->execute();

    while ($row = $stmt->fetch(PDO::FETCH_ASSOC)) {
        echo $row['id'];
    }
} catch (PDOException $e) {

}

预处理——查询4

<?php

try{
    $dsn = 'mysql:host=localhost;dbname=blog;charset=utf8';
    $pdo = new PDO($dsn , 'root' , 'kungezuishuai');

    $stmt = $pdo->prepare('select * from money where id > 3 order by id desc limit 0 , 5');

    $stmt->execute();
    $data = $stmt->fetchAll(PDO::FETCH_ASSOC);

    foreach ($data as $key => $val) {
        echo $val['username'].'<br />';
    }
} catch (PDOException $e) {

}

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