php--PDO的使用方式

PDO连接数据库，方式一

<?php
//数据源
$dsn = "mysql:dbname=test;host=localhost";
//异常
try
{
    //实例化
    $pdo = new PDO($dsn,"root","mysql123");
    echo "connect database ok.<br>\n";
    //查询语句
    $sql = "select * from user";
    //设置字符集
    $pdo->query("set names utf8");
    //循环取值
    foreach ($pdo->query($sql) as $row)
    {
        print_r($row);
        echo "<br>\n";
    }
}
//捕获异常
catch (PDOException $e)
{
    echo "connect database failed.<br>\n";
    print_r($e);
}

PDO连接数据库，方式二

<?php
//数据源
$dsn = "mysql:dbname=test;host=localhost";
//异常
try
{
    //实例化
    $pdo = new PDO($dsn,"root","mysql123");
    echo "connect database ok.<br>";
    //查询语句
    $sql = "select * from user";
    //设置字符集
    $pdo->query("set names utf8");
    //执行查询
    $result = $pdo->query($sql);
    //取值，返回数组
    while($row = $result->fetch(PDO::FETCH_ASSOC))
    {
        print_r($row);
    }
}
//捕获异常
catch (PDOException $e)
{
    echo "connect database failed.<br>\n";
    print_r($e);
}

PDO连接数据库，获取错误码

<?php

$dsn = "mysql:dbname=test;host=localhost";
try
{
    $pdo = new PDO($dsn,"root","mysql123");

}
catch (PDOException $e)
{
    echo "connect database failed.".$e->getMessage()."<br>";
}
//此表不存在
$sql = "insert into p values(null,'1','2')";
$pdo->exec($sql);
//获取错误码
echo "error:".$pdo->errorCode();

PDO连接数据库，获取错误详细信息

<?php
//数据源
$dsn = "mysql:dbname=test;host=localhost";
//异常
try
{
    $pdo = new PDO($dsn,"root","mysql123");
    $sql = "select bbb from user";
    $pdo->query("set names utf8");
    $pdo->query($sql);
    //异常码
    echo "errorcode:";
    echo $pdo->errorCode();
    echo "<br>\n";
    //异常详细信息
    echo "errorinfo:";
    print_r($pdo->errorInfo());



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