php实现购物车功能（下）

<?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括过,如果是则不会再次包括. 
 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(); 
?> 

function login($username,$password) //登录 
 { 
 $conn = db_connect(); //连接数据库 
 
 if(!$conn) 
 return 0; 
 
 //反省用户名唯一性 
 $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; 
 } 

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

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 /> 
 <?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>"; 
 } 

<?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,如果是则不会再次包括 
 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(); 
?> 

<?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,如果是则不会再次包括 
 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(); 
?> 

<?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,如果是则不会再次包括. 
 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(); 
?> 

<?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,如果是则不会再次包括. 
 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(); 
?> 

<?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); 
 ?> 
 <form method="post" action="<?php echo $edit ? 'edit_category.php' :'insert_category.php'; ?>"> 
 <table border="0"> 
  <tr> 
  <td>Category Name:</td> 
  <td><input type="text" name="catname" size="40" maxlength="40" value="<?php echo $edit ? $category['catname'] : ''; ?>"/></td> 
  </tr> 
  <tr> 
  <td <?php if(!$edit){echo "colspan=2";} ?> align="center"> 
  <?php 
  if($edit) 
  { 
   echo "<input type="hidden" name="catid" value="". $category['catid'] ."" />"; 
  } 
  ?> 
  <input type="submit" value="<?php echo $edit ? 'Update' : 'Add'; ?> Category"/></form> 
  </td> 
  <?php 
  if($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>"; 
  } 
  ?> 
  </tr> 
 </table> 
 <?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); 
 ?> 
 
 <form method="post" action="<?php echo $edit ? 'edit_book.php' : 'insert_book.php'; ?>"> 
 <table border="0"> 
 <tr> 
  <td>ISBN:</td> 
  <td><input type="text" name="isbn" value="<?php echo $edit ? $book['isbn'] : ''; ?>" /></td> 
 </tr> 
 <tr> 
  <td>Book Title:</td> 
  <td><input type="text" name="title" value="<?php echo $edit ? $book['title'] : ''; ?>" /></td> 
 </tr> 
 <tr> 
  <td>Book Author:</td> 
  <td><input type="text" name="author" value="<?php echo $edit ? $book['author'] : ''; ?>"/></td> 
 </tr> 
 <tr> 
  <td>Category:</td> 
  <td> 
  <select name="catid"> 
  <?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>"; 
  } 
  ?> 
  </select> 
  </td> 
 </tr> 
 <tr> 
  <td>Price:</td> 
  <td><input type="text" name="price" value="<?php echo $edit ? $book['price'] : ''; ?>" /></td> 
 </tr> 
 <tr> 
  <td>Description:</td> 
  <td><textarea rows="3" cols="50" name="description"><?php echo $edit ? $book['description'] : ''; ?></textarea></td> 
 </tr> 
 <tr> 
  <td <?php if (!$edit) { echo "colspan=2"; }?> align="center"> 
  <?php 
  if ($edit) 
  echo "<input type="hidden" name="oldisbn" value="".$book['isbn']."" />";?> 
  <input type="submit" value="<?php echo $edit ? 'Update' : 'Add'; ?> Book" /></form></td> 
  <?php 
  if ($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>"; 
 
  } 
  ?> 
  </td> 
 </tr> 
 </table> 
 </form> 
 <?php 
 } 
 
 function display_password_form() //显示更改暗码表单 
 { 
 ?> 
 <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 /> 
 <?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,$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; 
 } 
?>