Implement shopping cart function in php (Part 2)_php skills

Continue learning from the previous article: "PHP Implementing Shopping Cart Functions (Part 1)"

7. Implement a management interface

Login interface

is implemented by the following code:
7.1 admin.php

<&#63;php 
 
/** 
 * @author switch 
 * @copyright 2015 
 * 主管理菜单 
 */ 
 //require_once语句和require语句完全相同,唯一区别是PHP会检查该文件是否已经被包含过,如果是则不会再次包含。 
 require_once('book_sc_fns.php'); 
 
 session_start(); 
 
 if((@$_POST['username']) && (@$_POST['passwd'])) //尝试登陆 
 { 
 $username = $_POST['username']; 
 $passwd = $_POST['passwd']; 
 
 if(login($username,$passwd)) 
 { 
 $_SESSION['admin_user'] = $username; 
 } 
 else 
 { 
 do_html_header("Problem:"); 
 echo "<p>You could not be logged in.<br /> 
  You must be logged in to view this page.</p>"; 
 do_html_URL('login.php','Login'); 
 do_html_footer(); 
 exit; 
 } 
 } 
 
 do_html_header("Administration"); 
 
 if(check_admin_user()) 
 { 
 display_admin_menu(); 
 } 
 else 
 { 
 echo "<p>You are not authorized to enter the administration area.</p>"; 
 do_html_URL('login.php','Login'); 
 } 
 do_html_footer(); 
&#63;> 

7.2 Function login() in the user_auth_fns.php file

function login($username,$password) //登录 
 { 
 $conn = db_connect(); //连接数据库 
 
 if(!$conn) 
 return 0; 
 
 //检查用户名唯一性 
 $query = "select * from admin where username='". $username ."' 
  and password = sha1('". $password ."')"; 
 $result = $conn ->query($query); 
 
 if(!$result) 
 return 0; 
 
 if($result ->num_rows > 0) 
 return 1; 
 else 
 return 0; 
 } 

7.3 Function check_admin_user() in the user_auth_fns.php file

function check_admin_user() //检查是否是管理员 
 { 
 if(isset($_SESSION['admin_user'])) 
 return true; 
 else 
 return false; 
 } 

Management main interface

is implemented by the following code:

7.4 Function display_admin_menu() in the output_fns.php file

function display_admin_menu() //输出管理员菜单 
 { 
 ?> 
 <br /> 
 <a href="index.php">Go to main site</a><br /> 
 <a href="insert_category_form.php">Add a new category</a><br /> 
 <a href="insert_book_form.php">Add a new book</a><br /> 
 <a href="change_password_form.php">Change admin password</a><br /> 
 <&#63;php 
 } 
 
 function display_button($target,$image,$alt) //显示按钮 
 { 
 echo "<div align= \" center \"><a href=\"". $target ."\"> 
 <img src=\"images/". $image .".gif\" 
 alt=\"". $alt ."\" border = \" 0 \" height = \" 50 \" 
 width = \" 135 \" /></a></div>"; 
 } 

Directory added
Directory added successfully
You can see more Novel catalogs on the catalog page

is implemented by the following code:
7.5 insert_category_form.php

<&#63;php 
 
/** 
 * @author switch 
 * @copyright 2015 
 * 允许管理员向数据库中添加一个目录的表格 
 */ 
 //require_once语句和require语句完全相同,唯一区别是PHP会检查该文件是否已经被包含过,如果是则不会再次包含 
 require_once('book_sc_fns.php'); 
 session_start(); 
 
 do_html_header(); 
 if(check_admin_user()) 
 { 
 display_category_form(); 
 do_html_URL("admin.php","Back to administrtion menu"); 
 } 
 else 
 { 
 echo "<p>You are not authorized to enter the administation area.</p>"; 
 } 
 do_html_footer(); 
&#63;> 

7.6 insert_category.php

<&#63;php 
 
/** 
 * @author switch 
 * @copyright 2015 
 * 向数据库中插入新目录 
 */ 
 //require_once语句和require语句完全相同,唯一区别是PHP会检查该文件是否已经被包含过,如果是则不会再次包含 
 require_once('book_sc_fns.php'); 
 session_start(); 
 
 do_html_header("Adding a category"); 
 if(check_admin_user()) 
 { 
 if(filled_out($_POST)) 
 { 
 $catname =$_POST['catname']; 
 if(insert_category($catname)) 
 { 
 echo "<p>Category \"". $catname ."\" was added to the database.</p>"; 
 } 
 else 
 { 
 echo "<p>Category \"". $catname ."\" could not be added to the database.</p>"; 
 } 
 } 
 else 
 { 
 echo "<p>You have not filled out the form. Please try again.</p>"; 
 } 
 do_html_URL("admin.php","Back to administration menu"); 
 } 
 else 
 { 
 echo "<p>You are not authorised to view this page.</p>"; 
 } 
 do_html_footer(); 
&#63;> 

Administrator Directory Interface

Directory editing interface - can be updated and deleted

Directory updated successfully

You can see that the directory has been changed successfully on the directory main interface

is implemented by the following code:
7.7 edit_category_form.php

<&#63;php 
 
/** 
 * @author switch 
 * @copyright 2015 
 * 管理员编辑目录的表单 
 */ 
 //require_once语句和require语句完全相同,唯一区别是PHP会检查该文件是否已经被包含过,如果是则不会再次包含。 
 require_once('book_sc_fns.php'); 
 session_start(); 
 
 do_html_header("Edit category"); 
 if(check_admin_user()) 
 { 
 if($catname = get_category_name($_GET['catid'])) 
 { 
 $catid = $_GET['catid']; 
 $cat = compact('catname','catid'); 
 display_category_form($cat); 
 } 
 else 
 { 
 echo "<p>Could not retrieve category details.</p>"; 
 } 
 do_html_URL("admin.php","Back to administration menu"); 
 } 
 else 
 { 
 echo "<p>You are not authorized to enter the administration area.</p>"; 
 } 
 do_html_footer(); 
&#63;> 

7.8 edit_category.php

<&#63;php 
 
/** 
 * @author switch 
 * @copyright 2015 
 * 更新数据库中的目录 
 */ 
 //require_once语句和require语句完全相同,唯一区别是PHP会检查该文件是否已经被包含过,如果是则不会再次包含。 
 require_once('book_sc_fns.php'); 
 session_start(); 
 
 do_html_header("Updating category"); 
 if(check_admin_user()) 
 { 
 if(filled_out($_POST)) 
 { 
 if(update_category($_POST['catid'],$_POST['catname'])) 
 { 
 echo "<p>Category was updated.</p>"; 
 } 
 else 
 { 
 echo "<p>Category could not be updated.</p>"; 
 } 
 } 
 else 
 { 
 echo "<p>you have not filled out the form. Please try again.</p>"; 
 } 
 do_html_URL("admin.php","Back to administration menu"); 
 } 
 else 
 { 
 echo "<p>You are not authorised to view this page.</p>"; 
 } 
 do_html_footer(); 
&#63;> 

7.9 admin_fns.php

<&#63;php 
 
/** 
 * @author switch 
 * @copyright 2015 
 * 管理脚本使用的函数集合 
 */ 
 function display_category_form($category = '') //显示目录表单 
 { 
 //如果传入存在目录，进入编辑模式 
 $edit = is_array($category); 
 &#63;> 
 <form method="post" action="<&#63;php echo $edit &#63; 'edit_category.php' :'insert_category.php'; &#63;>"> 
 <table border="0"> 
  <tr> 
  <td>Category Name:</td> 
  <td><input type="text" name="catname" size="40" maxlength="40" value="<&#63;php echo $edit &#63; $category['catname'] : ''; &#63;>"/></td> 
  </tr> 
  <tr> 
  <td <&#63;php if(!$edit){echo "colspan=2";} &#63;> align="center"> 
  <&#63;php 
  if($edit) 
  { 
   echo "<input type=\"hidden\" name=\"catid\" value=\"". $category['catid'] ."\" />"; 
  } 
  &#63;> 
  <input type="submit" value="<&#63;php echo $edit &#63; 'Update' : 'Add'; &#63;> Category"/></form> 
  </td> 
  <&#63;php 
  if($edit) //允许删除存在目录 
  { 
  echo "<td> 
   <form method=\"post\" action=\"delete_category.php\"> 
   <input type=\"hidden\" name=\"catid\" value=\"". $category['catid'] ."\" /> 
   <input type=\"submit\" value=\"Delete category\" /> 
   </form></td>"; 
  } 
  &#63;> 
  </tr> 
 </table> 
 <&#63;php 
 } 
 
 function display_book_form($book = '') //显示图书表单 
 { 
 //如果传入图书存在，进入编辑模式 
 $edit = is_array($book); 
 &#63;> 
 
 <form method="post" action="<&#63;php echo $edit &#63; 'edit_book.php' : 'insert_book.php'; &#63;>"> 
 <table border="0"> 
 <tr> 
  <td>ISBN:</td> 
  <td><input type="text" name="isbn" value="<&#63;php echo $edit &#63; $book['isbn'] : ''; &#63;>" /></td> 
 </tr> 
 <tr> 
  <td>Book Title:</td> 
  <td><input type="text" name="title" value="<&#63;php echo $edit &#63; $book['title'] : ''; &#63;>" /></td> 
 </tr> 
 <tr> 
  <td>Book Author:</td> 
  <td><input type="text" name="author" value="<&#63;php echo $edit &#63; $book['author'] : ''; &#63;>"/></td> 
 </tr> 
 <tr> 
  <td>Category:</td> 
  <td> 
  <select name="catid"> 
  <&#63;php 
  $cat_array = get_categories(); 
  foreach($cat_array as $thiscat) 
  { 
   echo "<option value=\"". $thiscat['catid'] ."\""; 
   if(($edit) && ($thiscat['catid'] == $book['catid'])) 
   { 
   echo " selected"; 
   } 
   echo ">". $thiscat['catname'] ."</option>"; 
  } 
  &#63;> 
  </select> 
  </td> 
 </tr> 
 <tr> 
  <td>Price:</td> 
  <td><input type="text" name="price" value="<&#63;php echo $edit &#63; $book['price'] : ''; &#63;>" /></td> 
 </tr> 
 <tr> 
  <td>Description:</td> 
  <td><textarea rows="3" cols="50" name="description"><&#63;php echo $edit &#63; $book['description'] : ''; &#63;></textarea></td> 
 </tr> 
 <tr> 
  <td <&#63;php if (!$edit) { echo "colspan=2"; }&#63;> align="center"> 
  <&#63;php 
  if ($edit) 
  echo "<input type=\"hidden\" name=\"oldisbn\" value=\"".$book['isbn']."\" />";&#63;> 
  <input type="submit" value="<&#63;php echo $edit &#63; 'Update' : 'Add'; &#63;> Book" /></form></td> 
  <&#63;php 
  if ($edit) 
  { 
  echo "<td> 
   <form method=\"post\" action=\"delete_book.php\"> 
   <input type=\"hidden\" name=\"isbn\" value=\"".$book['isbn']."\" /> 
   <input type=\"submit\" value=\"Delete book\"/> 
  </form></td>"; 
 
  } 
  &#63;> 
  </td> 
 </tr> 
 </table> 
 </form> 
 <&#63;php 
 } 
 
 function display_password_form() //显示更改密码表单 
 { 
 &#63;> 
 <br /> 
 <form action="change_password.php" method="post"> 
 <table width="250" cellpadding="2" cellspacing="0" bgcolor="#cccccc"> 
  <tr> 
  <td>Old password:</td> 
  <td><input type="password" name="old_passwd" size="16" maxlength="16"/></td> 
  </tr> 
  <tr> 
  <td>New password:</td> 
  <td><input type="password" name="new_passwd" size="16" maxlength="16"/></td> 
  </tr> 
  <tr> 
  <td>Repeat new password:</td> 
  <td><input type="password" name="new_passwd2" size="16" maxlength="16"/></td> 
  </tr> 
  <tr> 
  <td colspan="2" align="center"><input type="submit" value="Change password"/></td> 
  </tr> 
 </table> 
 </form> 
 <br /> 
 <&#63;php 
 } 
 
 function insert_category($catname) //目录插入 
 { 
 $conn = db_connect(); //数据库连接 
 
 $query = "select * 
  from categories 
  where catname='". $catname ."'"; 
 $result = $conn ->query($query); 
 if((!$result) || ($result ->num_rows != 0)) 
 return false; 
 
 $query = "insert into categories values 
 ('','". $catname ."')"; 
 $result = $conn ->query($query); 
 if(!$result) 
 return false; 
 else 
 return true; 
 } 
 
 function insert_book($isbn,$title,$author,$catid,$price,$description) //图书插入 
 { 
 $conn = db_connect(); //连接数据库 
 
 $query = "select * from books 
  where isbn='". $isbn ."'"; 
 $result = $conn ->query($query); 
 if((!$result) || ($result ->num_rows != 0)) 
 return false; 
 
 $query = "insert into books values 
 ('". $isbn ."','". $author ."','". $title ."', 
 '". $catid ."','". $price ."','". $description ."')"; 
 
 
 $result = $conn ->query($query); 
 if(!$result) 
 return false; 
 else 
 return true; 
 } 
 
 function update_category($catid,$catname) //更改目录名称 
 { 
 $conn = db_connect(); //连接数据库 
 
 $query = "update categories 
  set catname='". $catname ."' 
  where catid='". $catid ."'"; 
 $result = @$conn ->query($query); 
 if(!$result) 
 return false; 
 else 
 return true; 
 } 
 
 function update_book($oldisbn,$isbn,$title,$author,$catid,$price,$description) 
 { 
 $conn = db_connect(); //连接数据库 
 
 $query = "update books 
  set isbn='". $isbn ."', 
  title='". $title ."', 
  author='". $author ."', 
  catid='". $catid ."', 
  price ='". $price ."', 
  description='". $description ."' 
  where isbn='". $oldisbn ."'"; 
 $result = @$conn ->query($query); 
 if(!$result) 
 return false; 
 else 
 return true; 
 } 
 
 function delete_category($catid) //删除目录 
 { 
 $conn = db_connect(); //连接数据库 
 
 $query = "select * 
  from books 
  where catid='". $catid ."'"; 
 $result = @$conn ->query($query); 
 if((!$result) || (@$result ->num_rows > 0)) //如果该目录有图书，无法删除该目录 
 return false; 
 
 $query = "delete from categories 
  where catid='". $catid ."'"; 
 $result = @$conn ->query($query); 
 if(!$result) 
 return false; 
 else 
 return true; 
 } 
 
 function delete_book($isbn) //删除图书 
 { 
 $conn = db_connect(); //连接数据库 
 
 $query = "delete from books 
  where isbn='". $isbn ."'"; 
 $result = @$conn ->query($query); 
 if(!$result) 
 return false; 
 else 
 return true; 
 } 
&#63;>

7.10 Catalog deletion operations, book addition, update, and deletion operations are basically similar to the above operations. They will not be demonstrated here. You can download the code to view

8. Extension
This project creates a fairly simple PHP shopping cart system. There are many improvements and enhancements we can make to it:

• In a real online store, some order recording and implementation system may have to be established - in this system, users cannot see the orders that have been reserved.
• Customers want to be able to check on the status of their order without having to contact us. Users should have a means of authentication that enables them to view their previous orders and also allow them to closely tie actions to their personal circumstances. It is also more convenient for us to collect some user habit information.
• Images of the book can be transferred to the site's image directory via a service such as FTP and given an appropriate name. You can upload files to the image insertion page to make this operation easier.
• You can add user login, personalized settings, book recommendations, online reviews, membership system, inventory level check, etc. There are so many features that can be added.

The above is all the code to implement the shopping cart function in PHP. I hope it will be helpful to everyone's learning.

Source code download: Shopping cart