Question Description
Im studying for my Computer Science class and dont understand how to answer this. Can you help me study?
Exercise 8-1
In this project, you will create a Web page that allows visitors to your
site to sign a guest book that is saved to a database.
1. Create a new document in your text editor and type the
declaration, element, document head, and
element. Use the strict DTD and Guest Book as the
content of the element.
2. Add the following text and elements to the document body:
Enter your name to sign our guest book
First Name
Last Name
3. Save the document as GuestBook.html in the Projects
directory for Chapter 8.
4. Create a new document in your text editor and type the
declaration, element, document head, and
element. Use the strict DTD and Sign Guest Book as
the content of the element.
5. Add the following script section to the document body:
6. Add the following statements to the script section to ensure
that visitors enter their ?rst and last names:
if (empty($_POST['?rst_name']) || empty($_
POST['last_name']))
echo "You must enter your ?rst and last
name! Click your browser's Back button to
return to the Guest Book form.";
7. Add the following statement to the script section to connect
to the database. Replace host with the host name of your
MySQL server, and user and password with the MySQL user
name and password you created in Chapter 7.
else {
$DBConnect = @mysql_connect("host", "user",
"password");
if ($DBConnect === FALSE)
echo "Unable to connect to the database
server."
. "Error code " . mysql_errno()
. ": " . mysql_error() . "";
8. Add the following statements to the end of the script section
to create a database named guestbook if it does not already
exist:
else {
$DBName = "guestbook";
if (!@mysql_select_db($DBName, $DBConnect)) {
$SQLstring = "CREATE DATABASE $DBName";
$QueryResult = @mysql_query($SQLstring,
$DBConnect);
if ($QueryResult === FALSE)
echo "Unable to execute the
query."
. "Error code " . mysql_
errno($DBConnect)
. ": " . mysql_error($DBConnect)
. "";
else
echo "You are the ?rst
visitor!";
}
mysql_select_db($DBName, $DBConnect);
9. Add the following statements to the end of the script section
to create a table named count if it does not already exist. The 489
table consists of a single auto-incrementing primary key ?eld
named countID.
$TableName = "visitors";
$SQLstring = "SHOW TABLES LIKE '$TableName'";
$QueryResult = @mysql_query($SQLstring, $DBConnect);
if (mysql_num_rows($QueryResult) == 0) {
$SQLstring = "CREATE TABLE $TableName
(countID SMALLINT
NOT NULL AUTO_INCREMENT PRIMARY KEY,
last_name VARCHAR(40), ?rst_name VARCHAR(40))";
$QueryResult = @mysql_query($SQLstring,
$DBConnect);
if ($QueryResult === FALSE)
echo "Unable to create the table."
. "Error code " . mysql_
errno($DBConnect)
. ": " . mysql_error($DBConnect) .
"";
10. Finally, add the following statements to the end of the script
section. These mysql_query() statements add the visitor to the
database. The last statement closes the database connection.
$LastName = stripslashes($_
POST['last_name']);
$FirstName = stripslashes($_
POST['?rst_name']);
$SQLstring = "INSERT INTO $TableName
VALUES(NULL, '$LastName',
'$FirstName')";
$QueryResult = @mysql_
query($SQLstring, $DBConnect);
if ($QueryResult === FALSE)
echo "Unable to execute the
query."
. "Error code " . mysql_
errno($DBConnect)
. ": " . mysql_
error($DBConnect) . "";
else
echo "Thank you for signing
our guest book!";
}
mysql_close($DBConnect);
}
}
11. Save the document as SignGuestBook.php in the Projects
directory for Chapter 8. Upload both SignGuestBook.php and
GuestBook.html to the server.
12. Open GuestBook.html in your Web browser by entering
the following URL: http:///PHP_Projects/
Chapter.08/Projects/GuestBook.html. Test the form to see if
you can add your name to the database.
13. Close your Web browser window.
