admin_fns.php

《PHP和MySQL Web开发》(第三版) Source

<?php
// This file contains functions used by the admin interface 
// for the Book-O-Rama shopping cart.

function display_category_form($category = '')
// This displays the category form.
// This form can be used for inserting or editing categories.
// To insert, don't pass any parameters.  This will set $edit
// to false, and the form will go to insert_category.php.
// To update, pass an array containing a category.  The
// form will contain the old data and point to update_category.php.
// It will also add a "Delete category" button.
{
  // if passed an existing category, proceed in "edit mode"
  $edit = is_array($category);

  // most of the form is in plain HTML with some
  // optional PHP bits throughout
?>
  <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)
       // allow deletion of existing categories 
       {
          echo '<td>';
          echo '<form method="post" action="delete_category.php">';
          echo '<input type="hidden" name="catid" value="'.$category['catid'].'">';
          echo '<input type="submit" value="Delete category">';
          echo '</form></td>';
       }
     ?>
  </tr>
  </table>
<?php
}

function display_book_form($book = '')
// This displays the book form.
// It is very similar to the category form.
// This form can be used for inserting or editing books.
// To insert, don't pass any parameters.  This will set $edit
// to false, and the form will go to insert_book.php.
// To update, pass an array containing a book.  The
// form will be displayed with the old data and point to update_book.php.
// It will also add a "Delete book" button.
{
  
  // if passed an existing book, proceed in "edit mode"
  $edit = is_array($book);

  // most of the form is in plain HTML with some
  // optional PHP bits throughout
?>
  <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
          // list of possible categories comes from database
          $cat_array=get_categories();
          foreach ($cat_array as $thiscat)
          {
               echo '<option value="';
               echo $thiscat['catid'];
               echo '"';
               // if existing book, put in current catgory
               if ($edit && $thiscat['catid'] == $book['catid'])
                   echo ' selected';
               echo '>'; 
               echo $thiscat['catname'];
               echo "\n"; 
          }
          ?>
          </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)
             // we need the old isbn to find book in database
             // if the isbn is being updated
             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>';
             echo '<form method="post" action="delete_book.php">';
             echo '<input type="hidden" name="isbn" 
                    value="'.$book['isbn'].'">';
             echo '<input type="submit" 
                    value="Delete book">';
             echo '</form></td>';
            }
          ?>
         </td>
      </tr>
  </table>
  </form>
<?php
}

function display_password_form()
{
// displays html change password form
?>
   <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>
   <br />
<?php
};

function insert_category($catname)
// inserts a new category into the database
{
   $conn = db_connect();

   // check category does not already exist
   $query = "select *
             from categories
             where catname='$catname'";
   $result = $conn->query($query);
   if (!$result || $result->num_rows!=0)
     return false;  

   // insert new category 
   $query = "insert into categories values
            ('', '$catname')"; 
   $result = $conn->query($query);
   if (!$result)
     return false;
   else
     return true;
}

function insert_book($isbn, $title, $author, $catid, $price, $description)
// insert a new book into the database 
{
   $conn = db_connect();

   // check book does not already exist
   $query = "select *
             from books 
             where isbn='$isbn'";

   $result = $conn->query($query);
   if (!$result || $result->num_rows!=0)
     return false;
 
   // insert new book
   $query = "insert into books values
            ('$isbn', '$author', '$title', '$catid', $price, '$description')";
  
   $result = $conn->query($query);
   if (!$result)
     return false;
   else
     return true;
}

function update_category($catid, $catname)
// change the name of category with catid in the database
{
   $conn = db_connect();

   $query = "update categories
             set catname='$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)
// change details of book stored under $oldisbn in
// the database to new details in arguments
{
   $conn = db_connect();

   $query = "update books
             set isbn='$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)
// Remove the category identified by catid from the db
// If there are books in the category, it will not
// be removed and the function will return false.
{
   $conn = db_connect();
   
   // check if there are any books in category 
   // to avoid deletion anomalies   
   $query = "select *
             from books
             where catid='$catid'";
   $result = @$conn->query($query);
   if (!$result || @$result->num_rows>0)
     return false;

   $query = "delete from categories 
             where catid='$catid'";
   $result = @$conn->query($query);
   if (!$result)
     return false;
   else
     return true; 
}


function delete_book($isbn)
// Deletes the book identified by $isbn from the database.
{
   $conn = db_connect();

   $query = "delete from books
             where isbn='$isbn'";
   $result = @$conn->query($query);
   if (!$result)
     return false;
   else
     return true;
}

?>