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我正在尝试从类中使用if条件访问我的函数，其中我的函数包含SQL语句我想要做的是使用if条件从另一个php文件访问它，如果它存在它将返回true。以下代码。

main.html中

< script type = "text/javascript"
src = "https://code.jquery.com/jquery-1.12.3.min.js" >
  < /script>
	
	<script>
				
	$(document).on("click", "#addBooksId", function() 
	{
      $.get("addBooks.html", function(data) 
	  { 
          $( "#myform" ).empty();
          $('#myform').append(data); / / Receive with value
alert('This is add books section');
});
});





< /script>

body {
  padding: 0;
  margin: 0;
  overflow-y: scroll;
  font-family: Arial;
  font-size: 15px;
}
#container {
  background-color: #707070;
}
#menu {
  width: 1250px;
  margin: 0 auto;
  text-align: left;
}
#menu ul {
  list-style-type: none;
  /*Remove bullets*/
  padding: 0;
  margin: 0;
  position: relative;
}
#menu ul li {
  display: inline-block;
}
#menu ul li:hover {
  text-decoration: none;
  color: black;
}
#menu ul li a,
visited {
  color: #CCC;
  /*Color of text*/
  display: block;
  /*Takes up the full width available*/
  padding: 15px;
  text-decoration: none;
}
#menu ul li a:hover {
  color: #CCC;
  text-decoration: none;
}
#menu ul li:hover ul {
  display: block;
}
#menu ul ul li {
  display: block;
}
#menu ul ul {
  display: none;
  position: absolute;
  background-color: #707070;
  min-width: 140px;
  /*Width when hover*/
}
#menu ul ul li a:hover
/*Color of text when hover*/

{
  color: #099;
}

<div id="container">

  <div id="menu">
    <ul>



      <li>

        <a href="#">Manage Books</a>

        <ul>
          <div id="addBooksId">
            <li><a href="#">Add Books</a>
            </li>
          </div>
        </ul>

      </li>





    </ul>
  </div>
</div>
<div id="myform">

  <p></p>
</div>

这是我的主页，用户可以在其中选择一个选项。单击下拉菜单中的选项后。它会将我重定向到addBooks.html，用户将填写以下文本字段。

addBooks.html

<style type="text/css"> .addBooks {
  clear: both;
  width: 800px;
  margin: 0 auto;
  margin-top: 10%;
}
.addBooks label {
  float: left;
  width: 150px;
  text-align: right;
}
.addBooks input {
  text-align: left;
  margin-left: 100px;
}
.addBooks select {
  text-align: left;
  margin-left: 100px;
}
</style>

<div id="container">

  <div class="addBooks">
    <h1>Add Books</h1>
    <hr>

    <form method="post" action="../process/bookProcess.php">

      <fieldset>

        <div class="form-field">
          <label for="name">Book Name:</label>
          <input type="text" id="name" name="bookName" required>
        </div>

        <br />

        <div class="form-field">
          <label for="edition">Edition:</label>
          <input type="text" id="edition" name="bookEdition" required>
        </div>

        <br />

        <div class="form-field">
          <label for="pages">Pages:</label>
          <input type="text" id="pages" name="bookPages" required>
        </div>

        <br />

        <div class="form-field">
          <label for="language">Language:</label>
          <input type="text" id="language" name="bookLanguage" required>
        </div>


        <div class="form-field">
          <input type="submit" id="submitBooks" value="Submit">
        </div>
      </fieldset>

    </form>

  </div>
  <!--- end of addBooks --->

</div>
<!--- end of container --->

connection.php

<?php
//PHP CONSTANTS
DEFINE ('host', 'localhost'); 
DEFINE ('username', 'root');
DEFINE ('password', '');
DEFINE ('database', 'librarysystem');

function getConnection()
{
$myDB = mysqli_connect(host,username,password,database);

if (!$myDB)
{
    trigger_error ('Could not connect to MySQL: ' . mysqli_connect_error());
}
else
{
    return $myDB;
}
}

?>

我创建了一个连接，所以我将从我想要使用的每个文件中调用它。在我的booksCRUD.php中，我创建了一个受保护的字符串，以便我可以在任何地方访问它。我已在登录中使用此方法。所以这是我第二次在INSERT语句中使用它。

bookCRUD.php

<?php
ini_set('display_errors', 1);
ini_set('display_startup_errors', 1);
error_reporting(E_ALL);

class booksCRUD{

    private $accessMyDB;

    public function __construct(){
       $this->accessMyDB = getConnection();
    } 

    public function createBook($dbBookName,$dbEdition,$dbPages,$dbLanguage){
        $statement = $this->accessMyDB->prepare("INSERT INTO bookmodule (bookName, bookEdition, bookPages, bookLanguage) VALUES (?, ?, ?, ?)");
        $statement->bind_param("ssss", $dbBookName,$dbEdition,$dbPages,$dbLanguage);

        if($statement->execute()){
            $statement->close();
            return true;
        }else{
            echo "Failed: " . $this->accessMyDB->error;
            return false;
        }
    }
}

?>

bookProcess.php

<?php
session_start();
ini_set('display_errors', 1);
ini_set('display_startup_errors', 1);
error_reporting(E_ALL);

require_once('../connection/connection.php');
require_once('../crud/bookCRUD.php');

if(isset($_POST['submitBooks'])){
    $dbBookName = $_POST['bookName'];
    $dbEdition = $_POST['bookEdition'];
    $dbPages = $_POST['bookPages'];
    $dbLanguage = $_POST['bookLanguage'];

    if(!empty($dbBookName) && !empty($dbEdition) && !empty($dbPages) && !empty($dbLanguage)){
        $obj = new booksCRUD();
        if(method_exists($obj,'createBook')){
           if($obj->createBook($dbBookName,$dbEdition,$dbPages,$dbLanguage)){
                echo "Successful!";
            }else{
                echo "error";
            }
        }else{
            // method doesn't exist
        }
    }else{
        echo "all fields are required";
    }
}
?>

我在if条件下创建了一个对象，但如果我做错了，我就无法访问我的函数。

Answer 1

使用method_exists()函数检查方法是否存在，然后调用方法，如下所示：

if(method_exists(new booksCRUD,'createBook')){
    // method exists
}else{
    // method doesn't exist
}

更新

您的代码中存在多个错误，例如：

请参阅此声明，

$dbLanguange = $_POST['bookLanguage'];
         ^ it should be $dbLanguage

查看if子句的条件

if(!empty($dbBookName) && !empty($dbEdition) && !empty($dbPages) && empty($dbLanguage))
                                                                    ^ it should be !empty($dbLanguage)

由于您不打算在课程$accessMyDB之外访问booksCRUD媒体资源，因此最好将其设为private。
请参阅此行，
```
echo "Error" . $mysqli->error();
```

您的连接处理程序$mysqli在此范围内不可用。

解决方案将保持您的 connection.php ，并更改您的 bookCRUD.php 和 bookProcess。 php 以下列方式：

<强> bookCRUD.php：

<?php

    class booksCRUD{

        private $accessMyDB;

        public function __construct(){
           $this->accessMyDB = getConnection();
        } 

        public function createBook($dbBookName,$dbEdition,$dbPages,$dbLanguage){
            $statement = $this->accessMyDB->prepare("INSERT INTO bookmodule (bookName, bookEdition, bookPages, bookLanguage) VALUES (?, ?, ?, ?)");
            $statement->bind_param("ssss", $dbBookName,$dbEdition,$dbPages,$dbLanguage);

            if($statement->execute()){
                $statement->close();
                return true;
            }else{
                echo "Failed: " . $this->accessMyDB->error;
                return false;
            }
        }
    }

?>

<强> bookProcess.php：

<?php

    session_start();
    require_once('../connection/connection.php');
    require_once('../crud/booksCRUD.php');

    if(isset($_POST['submitBooks'])){
        $dbBookName = $_POST['bookName'];
        $dbEdition = $_POST['bookEdition'];
        $dbPages = $_POST['bookPages'];
        $dbLanguage = $_POST['bookLanguage'];

        if(!empty($dbBookName) && !empty($dbEdition) && !empty($dbPages) && !empty($dbLanguage)){
            $obj = new booksCRUD();
            if(method_exists($obj,'createBook')){
               if($obj->createBook($dbBookName,$dbEdition,$dbPages,$dbLanguage)){
                    echo "Successful!";
                }else{
                    echo "error";
                }
            }else{
                // method doesn't exist
            }
        }else{
            echo "all fields are required";
        }
    }

?>

Answer 2

你的bookProcess.php中的

 if(!empty($dbBookName) && !empty($dbEdition) && !empty($dbPages) && empty($dbLanguage)) // If not empty
        {
$obj=new booksCRUD;//create object
$res=$obj->createBook($dbBookName,$dbEdition,$dbPages,$dbLanguage);//call FUNCTION HERE       

if($res==true){
echo "Successful!";
}
else{
echo "Error";
}
        }
        else
        {
            echo "Error POST Values are empty";
        }

如何从类访问函数到另一个php文件

2 个答案:

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