PHP的SQL查询插入-无法正常工作

Question

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我有此功能，它不会将数据保存到数据库。 类连接{public $ host =“ localhost”; public $ user =“ root”; public $ password =“”; 公开$ db =“ login”; 公共$ dbc;

        function __construct() {
        $con = mysqli_connect($this->host, $this->user, $this->password, $this->db);

        if(mysqli_errno($con)){
            echo"sum error";
        }else{
              $this->dbc = $con;
                    echo"connected ";
                 }
                }
            }



  <?php
  session_start();
  include_once("views/header.php");
  include_once("classes/functions.php");

  $userid = $_SESSION['userid'];
  $body = substr($_POST['body'],0,140);

  add_post($userid,$body);
  $_SESSION['message'] = "Your post has been added!";

  header("Location:information.php");



function add_post($userid,$body){
var_dump($userid);
    $sql = "INSERT INTO posts (user_id, body, stamp)
            values ($userid, '". mysqli_real_escape_string($con,$body). "',time())";

                die();
                if (mysqli_query($con, $sql)) {
                    echo "New record created successfully";

                } else {
                    echo "Error: " . $sql . "<br>" . mysqli_error($conn);
                }
                mysqli_close($con);

这是出现此错误的代码的最新部分：注意：未定义的变量：第34行的C：\\ xampp \\ htdocs \\ webpage \\ classes \\ functions.php中的con

                function add_post($userid,$body){
                $sql = "INSERT INTO posts (user_id, body, stamp) VALUES ($userid, $body, NOW())";
                $con;
                /* create a prepared statement */
                if ($stmt = $con->prepare($sql)) {

                    /* bind parameters for markers */
                    $stmt->bind_param("iss", $userid, $body, time());

                    /* execute query */
                    $stmt->execute();

                    if($id = $con->insert_id){
                        printf("New record created successfully, ID = %d\n", $id);
                    }else{
                        echo 'Did not insert any row';
                    }

                    /* close statement */
                    $stmt->close();
                }else{
                    echo "Error: " . $sql . "<br>" . mysqli_error($con);
                    }
                }

Answer 1

它一切都很好。 必须编辑代码的大部分才能正常工作。

  <?php
  session_start();
  include_once ("views/header.php");
  include_once ("classes/functions.php");

  $db = new connection();//instance of connection class
  $userid = $_SESSION['userid'];
  $body = substr($_POST['body'], 0, 140);
  $con = $db->get_connnetion();
  $insertCount = add_post($con, $userid, $body);
  if($insertCount > 0 ){
      $_SESSION['message'] = "Your post has been added!";
      header("Location:information.php");
  }else{
      echo "Your post has not been added!";
  }
  ?>