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php Limit query pdo with button next(下一步)按钮

limit pagination pdo sql php

Second View · 技术社区 · 6 年前

我的代码有什么问题。。我尝试单击“下一步”按钮以显示数据库中的下一条记录。。但当我点击时,什么都没发生。

这是我获取记录的函数

public function getBooks()
{
     $limit = 1;
     $start=0;

    //SELECT loginUser.username, Library.nameOfBook FROM loginUser JOIN userBook JOIN Library ON userBook.user_id = loginUser.id AND userBook.book_id = Library.id WHERE loginUser.username="loay";
    $query = "SELECT Library.nameOfBook FROM loginUser JOIN userBook JOIN Library ON userBook.user_id = loginUser.id AND userBook.book_id = Library.id WHERE loginUser.username=:username LIMIT $start, $limit";
    $statment = $this->db->prepare($query);
    $statment->execute([
        ':username' => $this->username
        //,':start' => $start, ':limit' => $limit
    ]);
    $result = $statment->fetchAll();

   echo "<table border='1'>
    <tr>
    <th>Books</th>
    </tr>";
    foreach($result as $row){
        echo "<tr>";
        echo "<td>" . $row['nameOfBook'] . "</td>";
        echo "</tr>";
    }
    echo "</table>";

}

这是我在索引中的代码。php

  $object->getBooks();

  if( isset($_POST['next'])){
    $start +=1;
}

这是我的表单代码

<form method="post" action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]);?>">
  Name: <input type="text" name="user" value="<?php echo $user;?>">
  <span class="error">* <?php echo $nameErr;?></span>
  <br><br>
  password: <input type="password" name="pass" value="<?php echo $password;?>" >
  <span class="error">* <?php echo $passwordErr;?></span>
  <br><br>
  <input type="submit" name="submit" value="Login">
  <br><br>

 
  <button type="button" name="button" onclick="window.location.href='/ooRigester.php'">SignUp</button>
  <br><br>
  <input type='submit' name='next' value='next' method="post"><br>
</form>

表单后的此代码

<?php
include_once('User.php');

if(isset($_POST['submit'])){

$username = $_POST["user"];
$password = $_POST["pass"];

$object = new User();
$object->username= $username;
$object->Password=$password;
if( $object->isAuthenticated() ){

  echo "User Verified . <br><br>";
  $object->getBooks();

  if( isset($_POST['next'])){
    $start +=1;
    $object->getBooks($start); 
}

}

else{

  echo "Wrong User Name Or Password . <br>";
}}


?>

这是在表单之前

<!DOCTYPE HTML>
<html>
<head>
<style>
.error {color: #FF0000;}
</style>
<title>Login Form</title>
</head>
<body>
<?php
/*$str = "Hello";
echo password_hash($str,1);*/
// define variables and set to empty values
$nameErr = "";
$passwordErr = "";
$user = "";
$password = "";

if ($_SERVER["REQUEST_METHOD"] == "POST") {
  if (empty($_POST["user"])) {
    $nameErr = "Name is required";
  } else {
    $user = test_input($_POST["user"]);
    // check if name only contains letters and whitespace
    if (!preg_match("/^[a-zA-Z ]*$/",$user)) {
      $nameErr = "Only letters and white space allowed";
    }
  }
  if (empty($_POST["pass"])) {
    $passwordErr = "Password is required";
  } else {
    $password = test_input($_POST["pass"]);
  }
  
}

function test_input($data) {
  $data = trim($data);
  $data = stripslashes($data);
  $data = htmlspecialchars($data);
  return $data;
}
?>

2 回复 | 直到 6 年前

Karlo Kokkak 6 年前

在里面 Index.php -您没有正确设置$起始值。以下代码集 $start 值来自 $_POST['start'] 如果不存在 $开始 默认值为0。

而且您也没有正确接受表单提交。我修改了代码,通过对它们的$\u POST变量进行isset()检查来接受这两种提交类型(next和login)。

使用:

<?php
include_once('User.php');

if(isset($_POST['submit']) OR isset($_POST['next'])){
    $username = $_POST["user"];
    $password = $_POST["pass"];

    $object = new User();
    $object->username= $username;
    $object->Password=$password;
    if( $object->isAuthenticated() ){

      echo "User Verified . <br><br>";

      $start = 0;
      if(isset($_POST['start'])){
         $start = $_POST['start'];
      }

      $object->getBooks($start);

    }
}
else{
  echo "Wrong User Name Or Password . <br>";
}


?>

在表单代码中,必须添加一个隐藏输入,该输入保存下一条数据库记录的偏移量值。

使用此代码:

<form method="post" action="">
  Name: <input type="text" name="user" value="<?php echo $user;?>">
  <span class="error">* <?php echo $nameErr;?></span>
  <br><br>
  password: <input type="password" name="pass" value="<?php echo $password;?>" >
  <span class="error">* <?php echo $passwordErr;?></span>
  <br><br>
  <input type="submit" name="submit" value="Login">
  <br><br>

  <input type="hidden" value="<?php echo (intval(isset($_POST['start'])?$_POST['start']:0)+1);?>" name="start"/>
  <button type="button" name="button" onclick="window.location.href='/ooRigester.php'">SignUp</button>
  <br><br>
  <input type='submit' name='next' value='next' method="post"><br>
</form>

你的课堂方法 getBooks() 必须有 $开始 参数,以便它知道下一个要显示的记录。

尝试:

public function getBooks($start = 0)
{
     $limit = 1;

    //SELECT loginUser.username, Library.nameOfBook FROM loginUser JOIN userBook JOIN Library ON userBook.user_id = loginUser.id AND userBook.book_id = Library.id WHERE loginUser.username="loay";
    $query = "SELECT Library.nameOfBook FROM loginUser JOIN userBook JOIN Library ON userBook.user_id = loginUser.id AND userBook.book_id = Library.id WHERE loginUser.username=:username LIMIT $start, $limit";
    $statment = $this->db->prepare($query);
    $statment->execute([
        ':username' => $this->username
        //,':start' => $start, ':limit' => $limit
    ]);
    $result = $statment->fetchAll();

   echo "<table border='1'>
    <tr>
    <th>Books</th>
    </tr>";
    foreach($result as $row){
        echo "<tr>";
        echo "<td>" . $row['nameOfBook'] . "</td>";
        echo "</tr>";
    }
    echo "</table>";
}

Tân Nguyá»n 6 年前

控制器中的代码:

function getBooks($start = 0)
{
    $limit = 1;

//SELECT loginUser.username, Library.nameOfBook FROM loginUser JOIN userBook JOIN Library ON userBook.user_id = loginUser.id AND userBook.book_id = Library.id WHERE loginUser.username="loay";
    $query = "SELECT Library.nameOfBook FROM loginUser JOIN userBook JOIN Library ON userBook.user_id = loginUser.id AND userBook.book_id = Library.id WHERE loginUser.username=:username LIMIT $start, $limit";
    $statment = $this->db->prepare($query);
    $statment->execute([
        ':username' => $this->username,
//,':start' => $start, ':limit' => $limit
    ]);
    $result = $statment->fetchAll();

    echo "<table border='1'>
            <tr>
                <th>Books</th>
            </tr>";

    foreach ($result as $row) {
        echo "<tr>";
        echo "<td>" . $row['nameOfBook'] . "</td>";
        echo "</tr>";
    }
    echo "</table>";
}

索引中的代码。php。

 $object->getBooks();

if( isset($_POST['next']))
{
    $start +=1;
    $object->getBooks($start);  
}