pagination not working properly - limit not being applied [duplicate] - php

Question

This question already has answers here:
"Notice: Undefined variable", "Notice: Undefined index", "Warning: Undefined array key", and "Notice: Undefined offset" using PHP
(29 answers)
Closed 8 years ago.
I am trying to add pagination to my search result, in doing so
I have encountered the following error at the following line:
Notice: Undefined variable: limit in C:\xampp\htdocs\t69\functions\functions.php on line 262
Below is line 262:
$get_crs = mysql_query("select * from books where book_provider='$provider_id' $limit");
Essentially I have a search results that should display only 10 items, if there is more than 10 item, it should show additional pages to navigate to (like page 1 - 5).
My problem is as follow The limit does not seem to apply well to the items being displayed, well more than 10 items are displayed, and I do not want to force to only display 10 such as LIMIT 10, because if there is more than 10 than only 10 would be displayed when I want that if theres more than 10 only 10 would be shown on that page with pagination shown at the bottom.
Below is portion of the code:
$outputList = '';
if(isset($_GET['provider'])){
$provider_id = $_GET['provider'];
global $con;
$get_crs = mysql_query("select * from books where book_provider='$provider_id' $limit");
$nr = mysql_num_rows($get_crs); // Get total of Num rows from the database query
if (isset($_GET['pg'])) { // Get pn from URL vars if it is present
$pn = preg_replace('#[^0-9]#i', '', $_GET['pg']);
//$pn = ereg_replace("[^0-9]", "", $_GET['pn']); // filter everything but numbers for security(deprecated)
} else { // If the pn URL variable is not present force it to be value of page number 1
$pn = 1;
}
//This is where we set how many database items to show on each page
$itemsPerPage = 10;
// Get the value of the last page in the pagination result set
$lastPage = ceil($nr / $itemsPerPage);
// Be sure URL variable $pn(page number) is no lower than page 1 and no higher than $lastpage
if ($pn < 1) { // If it is less than 1
$pn = 1; // force if to be 1
} else if ($pn > $lastPage) { // if it is greater than $lastpage
$pn = $lastPage; // force it to be $lastpage's value
}
// This creates the numbers to click in between the next and back buttons
// This section is explained well in the video that accompanies this script
$centerPages = "";
$sub1 = $pn - 1;
$sub2 = $pn - 2;
$add1 = $pn + 1;
$add2 = $pn + 2;
if ($pn == 1) {
$centerPages .= ' <span class="pagNumActive">' . $pn . '</span> ';
$centerPages .= ' ' . $add1 . ' ';
} else if ($pn == $lastPage) {
$centerPages .= ' ' . $sub1 . ' ';
$centerPages .= ' <span class="pagNumActive">' . $pn . '</span> ';
} else if ($pn > 2 && $pn < ($lastPage - 1)) {
$centerPages .= ' ' . $sub2 . ' ';
$centerPages .= ' ' . $sub1 . ' ';
$centerPages .= ' <span class="pagNumActive">' . $pn . '</span> ';
$centerPages .= ' ' . $add1 . ' ';
$centerPages .= ' ' . $add2 . ' ';
} else if ($pn > 1 && $pn < $lastPage) {
$centerPages .= ' ' . $sub1 . ' ';
$centerPages .= ' <span class="pagNumActive">' . $pn . '</span> ';
$centerPages .= ' ' . $add1 . ' ';
}
// This line sets the "LIMIT" range... the 2 values we place to choose a range of rows from database in our query
$limit = 'LIMIT ' .($pn - 1) * $itemsPerPage .',' .$itemsPerPage;
// Now we are going to run the same query as above but this time add $limit onto the end of the SQL syntax
// $sql2 is what we will use to fuel our while loop statement below
//////////////////////////////// END Adam's Pagination Logic ////////////////////////////////////////////////////////////////////////////////
///////////////////////////////////// Adam's Pagination Display Setup /////////////////////////////////////////////////////////////////////
$paginationDisplay = ""; // Initialize the pagination output variable
// This code runs only if the last page variable is ot equal to 1, if it is only 1 page we require no paginated links to display
if ($lastPage != "1"){
// This shows the user what page they are on, and the total number of pages
$paginationDisplay .= 'Page <strong>' . $pn . '</strong> of ' . $lastPage. ' ';
// If we are not on page 1 we can place the Back button
if ($pn != 1) {
$previous = $pn - 1;
$paginationDisplay .= ' Back ';
}
// Lay in the clickable numbers display here between the Back and Next links
$paginationDisplay .= '<span class="paginationNumbers">' . $centerPages . '</span>';
// If we are not on the very last page we can place the Next button
if ($pn != $lastPage) {
$nextPage = $pn + 1;
$paginationDisplay .= ' Next ';
}
}
while($row_crs = mysql_fetch_array($get_crs)){
$crs_id = $row_crs['course_id'];
$crs_cat = $row_crs['course_cat'];
$crs_provider = $row_crs['course_provider'];
$crs_title = $row_crs['course_title'];
$crs_price = $row_crs['course_price'];
$crs_city= $row_crs['course_city'];
$crs_date= $row_crs['course_date1'];
$crs_sdesc= $row_crs['course_sdesc'];
$crs_image = $row_crs['course_image'];
$outputList .= "
<article class='search-result row'><center>
<div class='col-xs-12 col-sm-12 col-md-3' id='thumbnailContainer'>
<a href='#' title='Lorem ipsum' class='thumbnail' id='resultThumbnail'><img src='content/logo_ontrack.png' /></a>
<button id='resultprice'><i class='fa fa-usd fa-2x'><span id='resultpriceText'> $crs_price</span></i></button>
</div>
<div class='col-xs-12 col-sm-12 col-md-2'>
<ul class='meta-search' id='listDesign'>
<li><button id='resultInfo'><i class='fa fa-calendar fa-1x'><span id='iconText'> $crs_date</span></i></button></li>
<li><button id='resultInfo'><i class='fa fa fa-tags fa-1x'><span id='iconText'> <b> Web Development</b></span></i></button></li>
<li><button id='resultInfo'><i class='fa fa-graduation-cap fa-1x'><span id='iconText'> <b> HOTT</b></span></i></button></li>
<li><button id='resultInfo'><i class='fa fa-map-marker fa-1x'><span id='iconText'> <b> $crs_city</b></span></i></button></li>
</ul>
</div></center>
<div class='col-xs-12 col-sm-12 col-md-7 excerpet'>
<h3 id='resultHeading'><a href='#' id='headingLinking'><b>$crs_title</b></a></h3>
<p id='courseshortDescription'>
$crs_sdesc
</p>
<center><button class='btn btn-danger' id='findoutBtn'><a href='details.php?crs_id=$crs_id' style='color:white;'>Find Out More</a></button></center>
<span class='clearfix borda'></span>
</article>
";
print "$outputList";
echo $paginationDisplay;
}
}
Any help would be greatly appreciated.
If you need any clarification, let me know.

Answer 1

$get_crs = mysql_query("select * from books where book_provider='$provider_id' $limit");
...
$limit = 'LIMIT ' .($pn - 1) * $itemsPerPage .',' .$itemsPerPage;
How do you expect to use $limit? It has to be defined before you use it.
For future, look more closely at the errors you get:
Notice: Undefined variable: limit in C:\xampp\htdocs\t69\functions\functions.php on line 262
Undefined variable: limit
Undefined variable: limit
Undefined variable: limit
Undefined variable: limit
on line 262

Answer 2

The error actually tells you the problem
Notice: Undefined variable: limit in C:\xampp\htdocs\t69\functions\functions.php on line 262
The limit needs to be declared before it is used.
Default your search criteria or switch these lines around.
$get_crs = mysql_query("select * from books where book_provider='$provider_id' $limit");
$limit = 'LIMIT ' .($pn - 1) * $itemsPerPage .',' .$itemsPerPage;

Answer 3

You need to replace:
$get_crs = mysql_query("select * from books where book_provider='$provider_id' $limit");
with:
$get_crs = mysql_query("SELECT * FROM `books` WHERE `book_provider`='$provider_id' LIMIT $limit");
I uppercased your SQL to make it more clear what is what in your formulated query (I also escaped database tables and column names. These are just best practices. Sorry I forgot to mention you need to actually define the limit as well.