PHP / SQL - 未选择数据库[关闭]

Question

我已经测试了我与数据库的连接并且它运行良好，直到我尝试插入数据库...并且我收到错误未选择数据库。提示/帮助将不胜感激，因为我对 PHP 还是很陌生！

我的代码如下：

<?php
    //connect to the database
    $con = new mysqli("localhost", "admin", "quixtar1");
    $con->select_db("attendance");
    //display success or failure
    if (mysqli_connect_errno()){
    echo "Failed to connect to MySQL: " . mysql_connect_error();
    }
    $ibonum = $_POST['num'];
    $course = $_POST['course'];

    $insert = "INSERT INTO tbltest (num, course) VALUES ($ibonum, $course)";

    $result = mysql_query($insert);
    if($result){
    echo("Success!");
    }
    else{
    echo ("Fail!  <br/>" . mysql_error());
    }
?>

Answer 1

你的代码应该是

<?php
//connect to the database
$con = new mysqli("localhost", "admin", "quixtar1", "attendance");
//display success or failure
if ($con){
    echo "Failed to connect to MySQL: " . $con->connect_error;
    exit;
}
$ibonum = $con->real_escape_string(htmlspecialchars($_POST['num']));
$course = $con->real_escape_string(htmlspecialchars($_POST['course']));

$insert = "INSERT INTO tbltest (num, course) VALUES ('$ibonum', '$course')";

$result = $con->query($insert);
if($result){
  echo("Success!");
}
else{
echo ("Fail!  <br/>" . $con->error);
}