创建数据库的连接（不同的方法）

<?php/** * Created by PhpStorm. * User: 程冬 * Date: 2017/7/24 * Time: 10:25 */

///**// * 面向对象化的方法// *///$mysqli = mysqli_init();//if (!$mysqli) {//    die(‘mysqli_init failed‘);//}////if (!$mysqli->options(MYSQLI_INIT_COMMAND, ‘SET AUTOCOMMIT = 0‘)) {//    die(‘Setting MYSQLI_INIT_COMMAND failed‘);//}////if (!$mysqli->options(MYSQLI_OPT_CONNECT_TIMEOUT, 5)) {//    die(‘Setting MYSQLI_OPT_CONNECT_TIMEOUT failed‘);//}////if (!$mysqli->real_connect(‘localhost‘, ‘root‘, ‘‘, ‘school‘)) {//    die(‘Connect Error (‘ . mysqli_connect_errno() . ‘) ‘//        . mysqli_connect_error());//}////if ($mysqli->connect_errno) {//    printf("Connect failed: %s\n", $mysqli->connect_error);//    exit();//}/////* Create table doesn‘t return a resultset *///if ($mysqli->query("CREATE TEMPORARY TABLE myuser LIKE user") === TRUE) {//    printf("Table myuser successfully created.\n");//}/////* Select queries return a resultset *///if ($result = $mysqli->query("SELECT userName FROM user LIMIT 10")) {//    printf("Select returned %d rows.\n", $result->num_rows);////    /* free result set *///    $result->close();//}/////* If we have to retrieve large amount of data we use MYSQLI_USE_RESULT *///if ($result = $mysqli->query("SELECT * FROM user", MYSQLI_USE_RESULT)) {////    /* Note, that we can‘t execute any functions which interact with the//       server until result set was closed. All calls will return an//       ‘out of sync‘ error */////    if (!$mysqli->query("SET @a:=‘this will not work‘")) {////        printf("Error: %s\n", $mysqli->error);////    }//    $result->close();//}////echo ‘Success... ‘ . $mysqli->host_info . "\n";////$mysqli->close();

//$link=mysqli_real_connect(‘127.0.0.1:3306‘,‘root‘,‘‘) or exit(‘连接失败...‘);//mysqli_select_db(‘pg39‘,$link);//$infos = mysqli_query(‘select * from student‘,$link);////$arr=array();//if($infos){//    while($info = mysqli_fetch_array($infos,MYSQL_BOTH)){//        array_push($arr,$info);//    }//}////mysqli_close($link);

/** * 连接数据库的mysqli函数库 * 使用的是过程化的风格编码 */

//    获取数据库的连接$link=mysqli_init();//    判断mysqli对象是否被创建成功if(!$link){    die(‘mysqli_init 创建失败...‘);}//    设置mysqli的参数值，这里是设置是否自动提交SQL语句if(!mysqli_options($link,MYSQLI_INIT_COMMAND,‘SET AUTOCOMMIT = 0‘)){    die(‘设置自动提交失败...‘);}//    设置连接的实效的时间，设置为5秒if(!mysqli_options($link,MYSQLI_OPT_CONNECT_TIMEOUT,5)){    die(‘设置连接的时间失败...‘);}//    创建mysqli连接数据库if(!mysqli_real_connect($link,‘localhost‘,‘root‘,‘‘,‘school‘)){    die(‘连接出现了错误(‘.mysqli_connect_errno().‘)‘);    mysqli_connect_error();}//    定义SQL语句并发送到数据库端执行操作且返回结果if(!mysqli_set_charset($link,‘utf8‘)){    die(‘设置数据库查询编码集失败...‘);}$infos=mysqli_query($link,‘select * from user‘,MYSQLI_USE_RESULT);//    处理返回结果$arr=array();if($infos){    while($info = mysqli_fetch_array($infos,MYSQLI_NUM)){        array_push($arr,$info);    }//    处理结束将获取到的数据集合清除    mysqli_free_result($infos);}var_dump($arr);//    关闭打开的资源mysqli_close($link);