PHP link only passing part of a mysql result - php

OK i have a php link which is made up of several variables
<a href=\year.php? manufacturer='.$manufacturer.'&fuel_type='.$fuel_type.'&model_type='.$model_type.'>'.$model_type.'</a>
The whole code is really long as it has a lot of pagination, so i will just include the basic query and the loop part.
$query1 = "SELECT Distinct model_type from $tableName where manufacturer='$manufacturer' AND fuel='$fuel_type' LIMIT $start, $limit";
$result = mysql_query($query1);
And then the bottom part where i get and show the results.
$count = 0;
$max = 2;
while($row = mysql_fetch_array($result))
{
$model_type = $row['model_type'];
$count++;
echo '<td class="manu"><div align="center">'.'<a href=\year.php? manufacturer='.$manufacturer.'&fuel_type='.$fuel_type.'&model_type='.$model_type.'>'.$model_type.'</a>'.'</div></td>';
if($count >= $max){
//reset counter
$count = 0;
//end and restart
echo '</tr><tr>';
}
}
now this works fine except when i take the mode type variable from the database it shows as 1 series, however when it is passed in this link it only gets the 1 and doesn't pick up the series.
Thanks

try to pass it like:
'.urlencode($model_type).'
Try To access it on next page with urldecode($_REQUEST['$model_type'])

I am not shure but you probably have a missing encoding Problem.
try this:
'.$model_type.'
Its url_encoding the values so your url doesnt get broken by ',",spaces and so on.
additional Hint:
Enclose your URL with " or ' so you do not get problems at the end.

Related

How to index a table with order by?

Using a while loop I'm able to return my table in the order I want, but after implementing pagination the variable I've created (counter) resets itself on each page, frustratingly. Example code:
$sql = ('SELECT id,name,logo FROM mytable ORDER BY name DESC LIMIT 25');
$query = mysqli_query($db_conx,$sql);
$counter = 0;
while ($row = $query->fetch_assoc()) {
$counter++;
echo "$counter, $row['id'], $row['name']";
echo "<br />";
}
I've tried many things and can't get this to work. Obviously my logic is flawed. The loop returns the correct results, but the $counter variable breaks on each page, resetting itself indefinitely.
What I am trying to do is get $counter to increase by 25 (representing results for each page) for each of the pages created by the pagination loop. Example code:
for ($i=1; $i<=$total_pages; $i++) {
echo "<a href='page.php?page=".$i."'>&nbsp[".$i."]</a> ";
$GLOBALS["counter"]+=25;
};
Obviously this was not working, so I am stumped at what I should try next. If anyone has any ideas I would love to hear them, I have heard great things about the SO community.
You seem to display only the first 25 results at any time.
You need to initialize $counter to zero if it's the first page, to 26 if it's the second page, and so on :
$counter = 0;
if(isset($_GET['counter'])){
$counter = intval($_GET['counter']);
}
You need to modify your query to fetch a different set of results for each page :
$sql = 'SELECT id,name,logo FROM mytable ORDER BY name DESC LIMIT ' . mysqli_real_escape_string($db_conx, $counter . ',25');
$query = mysqli_query($db_conx,$sql);
Then I assume you display a link to the other paginated pages, you need to pass it the value of $counter :
Next

PHP while loop to fetch post data from database

I am creating my own blog from scratch with a homepage that loads the latest posts in order of time published. I call the posts using a front controller and store the data on a MySQL database. The website itself is great and the posts all load perfectly with no issue. The issue is getting the homepage to work.
I created a few PHP functions for the homepage. They generally order the posts (database rows) by ID in descending order, since it's an autoincrement field, and call their data. And then to show the latest post as a sort of 'featured post' right at the top, by fetching the data from the very top row in the database, which is the latest post.
And that works fine - when I echo the result it shows the latest post just as I want it.
Below that I want two boxes, side by side, for the two posts before the first one. So I made this function to call them:
function fetch_rest_posts_1($conn) {
$stuff = $conn->query("SELECT * FROM table WHERE is_post = 1 ORDER BY id DESC LIMIT 1,2");
while ($row = $stuff->fetch_array()) {
$i=1;
return '<div id="post_'.$i.'" style="width:308px;height:215px;padding:5px">
<h2>'.$row['title'].'</h2>
<p>'.date('d/m/Y',strtotime($row['published_date'])).' by '.$row['author'].' | </p>
<p>'.$row['meta_description'].'</p>
</div>';
$i++;
} // style="white-space:nowrap;width:100%;overflow:hidden;text-overflow:ellipsis"
}
And it actually does work great when I echo the result, shows everything I want, but it only shows one div, not two. When I take the SQL query and directly enter it into phpMyAdmin, it gives me two rows. Have I done something wrong?
(I put the auto-increasing $i in there so that I could isolate each box and alter the style later.)
Your problem is caused by the return statement in the loop. You should add $return = '' at the top of your function, replace return by $result .=, and return $result at the end of your function.
In addition, the loop counter $i is reset in every iteration. Move the initial assignment out of the loop.
EDIT: The .= is intentional to append to $result instead of replacing it with another value constructed from the next dataset.
initiate $i outside the loop and use echo() instead of return()
return() breaks the loop
or use
$result .= '<div id="post_'.$i.'" style="width:308px;height:215px;padding:5px">
<h2>'.$row['title'].'</h2>
<p>'.date('d/m/Y',strtotime($row['published_date'])).' by '.$row['author'].' | </p>
<p>'.$row['meta_description'].'</p>
</div>';
and return $result; after the loop
That's because return will stop execution of the function try this approach:
function fetch_rest_posts_1($conn) {
$stuff = $conn->query("SELECT * FROM table WHERE is_post = 1 ORDER BY id DESC LIMIT 1,2");
$post = array();
while ($row = $stuff->fetch_array()) {
$post[] = $row;
}
return $post;
}
So the function purpose is to just get the data, so you can later print it:
$row = fetch_rest_posts_1($conn);
for($i = 0; count(row); $i++){
echo '<div id="post_'.$i.'" style="width:308px;height:215px;padding:5px">
<h2>'.$row[$i]['title'].'</h2>
<p>'.date('d/m/Y',strtotime($row['published_date'])).' by '.$row[$i]['author'].' | </p>
<p>'.$row[$i]['meta_description'].'</p>
</div>';
}

How do I get the first and last results from a query?

I am creating a pagination script and I need to get the first and last results in the database query so that I can determine what results appear when the user clicks a page to go to. This is the code that I have at the minute:
// my database connection is opened
// this gets all of the entries in the database
$q = mysql_query("SELECT * FROM my_table ORDER BY id ASC");
$count = mysql_num_rows($q);
// this is how many results I want to display
$max = 2;
// this determines how many pages there will be
$pages = round($count/$max,0);
// this is where I think my script goes wrong
// I want to get the last result of the first page
// or the first result of the previous page
// so the query can start where the last query left off
// I've tried a few different things to get this script to work
// but I think that I need to get the first or last result of the previous page
// but I don't know how to.
$get = $_GET['p'];
$pn = $_GET['pn'];
$pq = mysql_query("SELECT * FROM my_table ORDER BY id ASC LIMIT $max OFFSET $get");
// my query results appear
if(!$pn) {
$pn = 1;
}
echo "</table><br />
Page $pn of $pages<br />";
for($p = 1;$p<=$pages;$p++) {
echo "<a href='javascript:void(0);' onclick='nextPage($max, $p);' title='Page $p'>Page $p</a> ";
}
I think you have few problems there, but I try to tackle them for you. First, as comments say above, you are using code that it vulnerable to SQL injection. Take care of that - you might want to use PDO, which is as easy use as MySQL extension, and will save you from many trouble (like injection).
But to your code, lets go through it:
You should ask DB to get count of the rows, not using mysql function, it's far more effective, so use SELECT count(*) FROM mytable.
For $pages use ceil() as you want all rows to be printed, if you have $max 5 and have 11 rows, round will make $pages 2, where you actually want 3 (last page just contains that last 11th row)
in LIMIT you want to LIMIT row_count OFFSET offset. You can calculate offset from page number, so: $max = row_count but $offset = ($max * $page) - $max. In your code if $get is directly the page, it means you get $get'th row (Not sure though what happens in your JS nextpage. Bare in mind that not all use JavaScript.)
I have prepared simple example here which uses PDO, maybe that gives you idea how simple it's use PDO.
The selecting rows shows example how to put parameters in SQL, it would be perfectly safe in this case state, 'SELECT * FROM pseudorows LIMIT '.$start.','.$max by I wanted to make an example how easy it is (and then safe):
// DB config
$DB_NAME = 'test';
$DB_USER = 'test';
$DB_PASSWD = 'test';
// make connection
try {
$DB_CONN = new PDO("mysql:host=localhost;dbname=".$DB_NAME, $DB_USER, $DB_PASSWD);
$DB_CONN->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
} catch (PDOException $e) {
die($e);
}
// lets say user param 'p' is page, we cast it int, just to be safe
$page = (int) (isset($_GET['p'])?$_GET['p']:1);
// max rows in page
$max = 20;
// first select count of all rows in the table
$stmt = $DB_CONN->prepare('SELECT count(*) FROM pseudorows');
$stmt->execute();
if($value = $stmt->fetch()) {
// now we know how many pages we must print in pagination
// it's $value/$max = pages
$pages = ceil($value[0]/$max);
// now let's print this page results, we are on $page page
// we start from position max_rows_in_page * page_we_are_in - max_rows_in_page
// (as first page is 1 not 0, and rows in DB start from 0 when LIMITing)
$start = ($page * $max) - $max;
$stmt = $DB_CONN->prepare('SELECT * FROM pseudorows LIMIT :start,:max');
$stmt->bindParam(':start',$start,PDO::PARAM_INT);
$stmt->bindParam(':max', $max,PDO::PARAM_INT);
$stmt->execute();
// simply just print rows
echo '<table>';
while($row = $stmt->fetch()) {
echo '<tr><td>#'.$row['id'].'</td><td>'.$row['title'].'</td></tr>';
}
echo '</table>';
// let's show pagination
for($i=1;$i<=$pages;$i++) {
echo '[ '.$i.' ]';
}
}
mysql_fetch_array returns an associative array
Which means you can use reset and end to get the first and last results:
$pqa = mysql_fetch_array($pq);
$first = reset($pqa);
$last = end($pqa);
I don't see how you plan to use the actual results, just page numbers should be sufficient for pagination.
Still, hope it helps. And yes, upgrade to mysqli, so your code doesn't get obsolete.

How to php pagination of results obtained from this database

I am a beginner in php.
I visualize in my html page the results obtained with this php code, and now I want to paginate the results and limit your search to 6 items per page. How can I get this? My php code is as follows:
<?php
$k = $_GET['k'];
$terms = explode(" ", $k);
$query = "SELECT * FROM table_name WHERE ";
$i = 0;
foreach ($terms as $each){
$i++;
if ($i == 1)
$query .= "keywords LIKE '%$each%' ";
else
$query .= "OR keywords LIKE '%$each%' ";
}
// connect
mysql_connect("hostname","databaseUser","databasePassword");
mysql_select_db("databaseName");
$query = mysql_query($query);
$numrows = mysql_num_rows($query);
echo "<p><strong>Totale: {$numrows} risultati trovati</strong></p></br>";
if ($numrows > 0){
while ($row = mysql_fetch_assoc($query)){
$id = $row['id'];
$title = $row['title'];
$description = $row['description'];
$keywords = $row['keywords'];
$link = $row['link'];
$date = $row['date'];
$caption = $row['caption'];
echo "<h4><a href='$link'>$title</a></h4>";
echo "<em>$description</em></br></br>";
echo "$caption</br>";
echo "$link</br></br>";
echo "<em>$date</em></br></br>";
}
}
else
echo "NO result found for \"<p><strong>$k</strong></p>\"";
// disconnect
mysql_close();
?>
Pagination is a problem that most of us have tried to solve over the years.
You can build your own library to do this but you'll almost definitely be re-inventing the wheel and might not spot/handle some of the special cases.
If you're using a framework I'd suggest using the built in paginator, if not you could look at using something like http://pear.php.net/package/Pager which is a PEAR package.
You need to add a page variable into your code. The easiest way to to this is via $_GET, just like you grabbed keywords, so your url should look something like this:
foo.php?k=keywords%20here&p=1
Where p is the current page number.
Then you just need to add a limit to your search results so that you only grab 6, and the correct 6 at that. Something like this:
$query .= ' LIMIT '.(6*($pageNum - 1)).' 6';
This statement tells SQL to start at the first entry for the given page, and grab 6 results. We subtract 1 from the page number so that page 1 starts at entry 0 instead of entry 6.
The result of this code:
page | statement | Rows Grabbed
---------------------------------
1 | LIMIT 0 6 | 1-6
2 | LIMIT 6 6 | 7-12
3 | LIMIT 12 6 | 13-18
---------------------------------
and so on...
You might need to check that $_GET['p'] is an integer before you put it in $pageNum, so that you don't run into runtime issues trying to multiply a string by 6.
If you ever want to change the results per page, simply replace the 6's in that statement with the desired number of results per page, e.g.
$query .= ' LIMIT '.($numResults*($pageNum - 1)).' '.$numResults;
That way you can set your desired number of results with another variable, say $_GET['n'] or something similar, and have even better control.
EDIT:
You should probably add error checking:
$pageNum = (is_numeric($_GET['p']) ? intval($_GET['p']) : 1);
which says if GET[p] is numeric, set pageNum to the integer value of GET[p]. Otherwise, set pageNum to 1.
Also, You have a few errors in the way that you put variables into strings. There are two ways to join a variable into a string, you can either use double quotes and curly braces, like so:
$string = "this string has {$variable} in it";
Or you can concatenate with periods, using either single or double quotes likes so:
$string = 'this string has ' . $variable . " in it";
You have this problem in your foreach loop when you append the query, and also further down where you output your results.

PHP/MySQL Count() Issue

I am trying to create a class registration system for a client that utilizes PHP and MySQL. I have the database and table all set up and that part works just fine, however, the client has requested that upon registration, if there are 3 or fewer students enrolled to warn that the class may not run.
I'm trying to use the count() function as well as passing a dynamic variable from a cookie, set from the registration PHP script. However, I've hit a roadblock. I can't seem to get the count() function to actually count the rows. My select statement is below. Any help would be greatly appreciated.
$class = $_COOKIE["class"];
$min_check = "SELECT class_list, COUNT(class_list) as count
FROM T_Student WHERE class_list = '$class'
GROUP BY class_list
HAVING count < 20";
$result = mysql_query($min_check);
$count = mysql_num_rows($result);
if ($count < 4)
{
echo "IF THERE ARE 3 OR FEWER PEOPLE SIGNED UP FOR THIS CLASS, IT MAY NOT RUN.\n";
echo "THERE ARE CURRENTLY " . $count . " PEOPLE SIGNED UP.\n";
}
else if ($count > 4)
{
echo "There are currently " . $count . " people signed up for this class.";
}
?>
Your SQL query is returning a list of the class_list values, along with a count of each specific instance, where there are less than 20 people registered.
$count = mysql_num_rows($result);
...is getting the number of records returned in the resultset, not the alias count value, which is why you aren't seeing the output you expect. You need to read into your resultset to get the value:
while ($row = mysql_fetch_assoc($result)) {
$count = $row['count'];
if($count < 4) { ... }
}
The count that you want is returned in the row of the query. the mysql_num_rows will count the rows returned, which is not what you want. Use this instead.
$result = mysql_query($min_check);
$count = mysql_fetch_row($result);
$count = $count[0];
On a first glance, the HAVING count < 20 is unnecessary.
You use the MySQL-count-function, but never retrieve it's value!? Use:
$firstRow = mysql_fetch_row($result);
$count = $firstRow[1]; // 1 indicates the second column (0 being the first)
I don't recommend using known MySQL identifiers like count. It's confusing.
$class = mysql_real_escape_string($_COOKIE["class"]);
$min_check = "SELECT class_list, COUNT(class_list) as mycount
FROM T_Student WHERE class_list = '$class'
GROUP BY class_list
HAVING mycount < 20";
Don't forget to escape the contents of that cookie!
The error is that count is a reserved word. You need to either surround it in backticks `count` or even better, use a different moniker. It's not an error per se, but it's just too confusing.
Next up, you are not actually retrieving the mycount result from the database. I suggest using code something like this:
$result = mysql_query($min_check);
while( $row = mysql_fetch_assoc($result) ) {
$people_count = $row['mycount'];
if ($people_count < 4) { echo "this" }
else { echo "that" }
}

Categories