php操作数据库

<?php

session_start();

#面向过程

function create_connection(){

    $conn = mysqli_connect('127.0.0.1','root','123456','learn_2') or die("数据库连接失败");

    mysqli_query($conn,"set names utf8");

    return $conn;

}

#面向对象

function create_connection_opp(){

    $conn = new mysqli('127.0.0.1','root','123456','learn_2') or die("数据库连接失败");

    $conn->query("set names utf8");

    #$conn->set_charset('utf8');

    return $conn;

}

function test_mysqli_opp(){

    $conn = create_connection_opp();

    $sql = "select * from user";

    $result = $conn->query($sql);

    //获取结果集行数

    #echo $result->num_rows;

    $rows = $result->fetch_all();

    var_dump($rows);

    #关联数组的方式

    $rows = $result->fetch_all(MYSQLI_ASSOC);

    var_dump($rows);

    foreach ($rows as $row){

        echo $row['username']."<br>" ;

        echo $row['password'];

    }

}

//mysql预处理功能

function mysqli_prepare_stmt(){

    $conn  =create_connection_opp();

    $sql = "select * from user where username = ?";

    //实例化prepared statement预处理对象

    $stmt = $conn->prepare($sql);

    #实例化需要将参数进行绑定 "s"代表字符串  "i"整数   "d"小数  "b"二进制

    $stmt->bind_param("s",$username);

    $username = 'zs';

    #要获取查询结果，还需要绑定结果参数。不需要返回结果无需此操作

    $stmt->bind_result($username,$password);

    #返回值bool  ture执行成功  false执行失败

    $stmt->execute();

    #调佣结果并进行处理

    $stmt->store_result();

    while($stmt->fetch()){

        echo $username,$password,'<br>';

    }

    #输出行数  

    echo $stmt->num_rows.'<br>';

    echo $stmt->affected_rows;

   

    /**

     *     $sql = "select * from user where username = ? and password = ?";

     *     $stmt->bind_param("ss",$username,$password);

     */

     

}

mysqli_prepare_stmt()

?>