PHP and MySQL Web Development - P122 pdf

$HTTP_POST_FILES['picture']['type']; } } header'Location: '.$HTTP_POST_VARS['destination']; ?> The delete story link calls delete_story.php, which actions a simple DELETEstatement and re

(headline, story_text, page, writer, created, modified) values

('$headline', '$story_text', '$page', '"

.$HTTP_SESSION_VARS['auth_user']."', $time, $time)";

}

$result = mysql_query($sql, $conn);

if (!$result) { print "There was a database error when executing <pre>$sql</pre>";

print mysql_error();

exit;

}

if ( (isset($HTTP_POST_FILES['picture']['name']) &&

is_uploaded_file($HTTP_POST_FILES['picture']['tmp_name']))) {

if (!isset($story))

$story = mysql_insert_id();

$type = basename($HTTP_POST_FILES['picture']['type']);

switch ($type) { case 'jpeg':

case 'pjpeg': $filename = "pictures/$story.jpg";

move_uploaded_file($HTTP_POST_FILES['picture']['tmp_name'],

$filename);

$sql = "update stories

set picture = '$filename' where id = $story";

$result = mysql_query($sql, $conn);

break;

default: print 'Invalid picture format: '

$HTTP_POST_FILES['picture']['type'];

} }

header('Location: '.$HTTP_POST_VARS['destination']);

?>

The delete story link calls delete_story.php, which actions a simple DELETEstatement and returns the writer to the calling page.The code for delete_story.phpis shown in Listing 26.8.

Listing 26.7 Continued

Listing 26.8 delete_story.php—Is Used to Delete a Story from the Database

<?php

// delete_story.php

include('include_fns.php');

$conn = db_connect();

$story = $HTTP_GET_VARS['story'];

$sql = "delete from stories where id = $story";

$result = mysql_query($sql, $conn);

header('Location: '.$HTTP_SERVER_VARS['HTTP_REFERER']);

?>

Searching

Clicking the keywords link on the stories list brings up a new form for entering key-words against the story.There is no limit to the number of keykey-words that can be entered, and each keyword is given a weight value, with a higher value indicating that it is more relevant.

Figure 26.7 shows the screen used to set keywords against a particular story.

Figure 26.7 Setting keywords for a story.

The script keywords.phpis fairly straightforward, so we won’t look at it in any detail It

is included on the CD-ROM.

This script triggers the keyword_add.phpand keyword_delete.phpscripts.These scripts are also straightforward, and are therefore not included here.

The script keyword_add.phpuses the following query to add new keywords to the database:

insert into keywords (story, keyword, weight) values ($story, '$keyword', $weight)

In a similar vein,keyword_delete.phpuses the following query to remove a keyword:

delete from keywords where story = $story and keyword = '$keyword'

What is interesting is the way in which the weight values are used to calculate a percent-age relevance figure when searching.

The search form in search_form.phpcontains a single field for keywords, and sub-mits to search.php, which queries the database of live stories to find matching content.

The source for search.phpis shown in Listing 26.9.

Listing 26.9 search.php—Finds Matching Stories and Calculates a Percentage Match

Score

<?php

include('include_fns.php');

include('header.php');

$conn = db_connect();

if ($HTTP_POST_VARS['keyword']) {

$k = split(' ', $HTTP_POST_VARS['keyword']);

$num_keywords = count($k);

for ($i=0; $i<$num_keywords; $i++) {

if ($i)

$k_string = "or k.keyword = '".$k[$i]."' ";

else

$k_string = "k.keyword = '".$k[$i]."' ";

}

$and = "and ($k_string) ";

$sql = "select s.id,

s.headline,

10 * sum(k.weight) / $num_keywords as score from stories s, keywords k

$and group by s.id, s.headline order by score desc, s.id desc";

$result = mysql_query($sql, $conn);

} print '<h2>Search results</h2>';

if ($result && mysql_num_rows($result)) { print '<table>';

while ($qry = mysql_fetch_array($result)) { print '<tr><td>';

print $qry['headline'];

print '</td><td>';

print floor($qry['score']).'%';

print '</td></tr>';

} print '</table>';

} else { print 'No matching stories found';

} include('footer.php');

?>

First, the keyword string passed into the script is split up into individual search words.

We are not using any advanced search techniques in this example, such as allowing the searcher to use ANDor ORkeywords or group words together into a phrase.

if ($HTTP_POST_VARS['keyword']) {

$k = split(' ', $HTTP_POST_VARS['keyword']);

$num_keywords = count($k);

for ($i=0; $i<$num_keywords; $i++) {

if ($i)

$k_string = "or k.keyword = '".$k[$i]."' ";

else

$k_string = "k.keyword = '".$k[$i]."' ";

}

$and = "and ($k_string) ";

This code uses the PHP function split()to create an array containing each word in the keywordstring separated by a space character If only one word is specified, it still returns a single element array and the subsequent loop is executed once Ultimately the condition stored in $andwill look something similar to

Listing 26.9 Continued

The search query built based on the previous code would be select s.id,

s.headline,

10 * sum(k.weight) / $num_keywords as score from stories s, keywords k

where s.id = k.story and (k.keyword = 'keyword1'

or k.keyword = 'keyword2'

or k.keyword = 'keyword3') group by s.id, s.headline order by score desc, s.id desc

The calculation for the score is the sum of the weights from all matching keywords divided by the number of keywords searched for and then multiplied by ten.This favors searches in which all the keywords entered match the keywords in the database.

Because the weights range from 1 to 10, the maximum value for the score is 100 A search for three keywords would only be a 100% match with a story if all three were found for that story and each had a weight of 10.

Editor Screen

The only part of the system we haven’t covered is how a story actually gets published after it has been written.The script publish.phpmakes a story live It is shown in Listing 26.10.

Listing 26.10 publish.php—Lists All Documents So the Editor Can Choose Which

Ones Are Shown on the Live Site

<?php

include('include_fns.php');

$conn = db_connect();

$sql = 'select * from stories order by modified desc';

$result = mysql_query($sql, $conn);

print '<h2>Editor admin</h2>';

print '<table>';

print '<tr><th>Headline</th><th>Last modified</th></tr>';

while ($story = mysql_fetch_array($result)) { print '<tr><td>';

print $story['headline'];

print '</td><td>';

print date('M d, H:i', $story['modified']);