[PHP知识库]PHP连接数据库

<?php
    $userName=$_POST["userName"];
    $userPwd=$_POST["userPwd"];
    if(empty(trim($userName)) || empty(trim($userPwd)))
        echo("失败<br>");
    else
        echo("成功<br>");
    // 连接数据库
    $link = mysqli_connect('localhost','root','123456','mytest');
    if(!$link){
        echo("NO<br>");
    }
    else{
        echo("OK<br>");
    }
    $sql = "SELECT * FROM student";
    $result = mysqli_query($link,"INSERT INTO student(ID,name) VALUES(12435,'Zcm')");
    if($result){
        echo "插入成功！";
    }
    else{
        // mysqli_error($link)显示错误信息
        echo "插入失败！".mysqli_error($link);
    }
    $result = mysqli_query($link,$sql);
    if (mysqli_num_rows($result) > 0) {
        // 输出数据
        while($row = mysqli_fetch_assoc($result)) {
            echo "id: " . $row["ID"]. " - Name: " . $row["name"]. "<br>";
        }
    } else {
        echo "0 结果";
    }
?>