I'm making news website, and I have mysql db with field "time" like 1533074400
Everything is ok if I just print results from query, but if I want to print only news older than today, I get in result only 2 instead of 5 news on first page. Remaining 3 are on the second page.
The problem is with query, if I receive let's say I have in my database 10 results and only 7 of them are past news, so when I filter them descending by
if ($today > news_date)
I get 2 news on first page (the remaining 3 are invisible future news, blocked by code above) and the rest 5 news on second page. So my question is, what to do to get it properly: 5 news on first page and remaining 2 on second page?
$results_per_page = 5;
if (!isset($_GET['page'])) {
$page = 1;}
else {
$page = $_GET['page'];
}
$this_page_first_result = ($page-1)*$results_per_page;
$sql='SELECT * FROM news ORDER BY time DESC LIMIT ' . $this_page_first_result . ',' . $results_per_page;
$result = mysqli_query($con, $sql);
$number_of_results = mysqli_num_rows($result);
$today = strtotime("now");
while($row = mysqli_fetch_array($result))
{
$news_date = $row[1];
if ($today > $news_date) {
echo HTML;
}
}
$number_of_pages = ceil($number_of_results/$results_per_page);
for ($page=1;$page<=$number_of_pages;$page++) {
echo '' . $page . ' ';
}
Try this:
$sql='SELECT * FROM news WHERE time < '.time().' ORDER BY time DESC LIMIT ' . $this_page_first_result . ',' . $results_per_page;
//Note: time() is an equivalent to strtotime("now")
If you're doing pagination in MySQL you should also do your filtering inside MySQL.
[Edit: Additional explanation] If you paginate in MySQL and then filter in PHP you'll have weird instances like this crop up because MySQL doesn't know where you're intending to actually start from. In this particular example if you have a lot of future-dated items you could actually end up with several blank pages of results pages before you start to see entries.
[Edit edit:] Also, if you do this, you'll no longer need the if check in your PHP loop as MySQL will have already done that.
Related
I didn't know exactly how to word this question but by do something I mean that I would like to hide or not show my "next" button that is shown below. I have a script that pulls all the images from MySQL and prints them to my page by 30 images per page and the next 30 will create a new page that is activated by my back/next buttons. My "back" button has a if statement if $startrow isn't >= 0 than it won't show but I would like the same concept with my next button when the last row in my database is shown and it hides my next button.
I was thinking if you can detect the first empty row or the last row of the database and if so hide the next button. Otherwise it keeps adding 30 to $startrow when nothing is shown on screen.
I found a script helping me with this here but it didn't tell me how to hide the next button.
<?php
$startrow = $_GET['startrow'];
if (!isset($_GET['startrow']) or !is_numeric($_GET['startrow'])) {
$startrow = 0;
} else {
$startrow = (int)$_GET['startrow'];
}
?>
<?php
$db = mysqli_connect("localhost", "root", "", "media");
$uploaded = mysqli_query($db, "SELECT * FROM images LIMIT $startrow, 30");
while ($row = mysqli_fetch_array($uploaded)) {
echo "<div class='img_container'>";
echo "<li><img class='img_box' src='uploads/images/".$row['image_title']."' ></li>";
echo "</div>";
}
$prev = $startrow - 30;
if ($prev >= 0) {
echo '<div class="prevRow">Back</div>';
}
echo '<div class="nextRow">Next</div>';
?>
You could try something like
$num_rows = 30; // rows on a page
$db = mysqli_connect("localhost", "root", "", "media");
// get total possible rows
$res = mysqli_query($db, "SELECT count(id) FROM images");
$row = $res->fetch_row();
$total_rows = $row[0];
$res->close();
$uploaded = mysqli_query($db, "SELECT * FROM images LIMIT $startrow, $num_rows");
while ($row = mysqli_fetch_array($uploaded)) {
. . .
}
$prev = $startrow - $num_rows;
if ($prev >= 0) {
echo '<div class="prevRow">Back</div>';
}
if ( $startrow+$num_rows < $total_rows ) {
echo '<div class="nextRow">Next</div>';
}
Potentially a little faster than the answer from #RiggsFolly, you can modify your existing query to count the rows.
SELECT SQL_CALC_FOUND ROWS * FROM images LIMIT $startrow, 30
Then, after the query returns, you run a second query to get the answer:
SELECT FOUND_ROWS()
The FOUND_ROWS() function returns the number of rows the previous query would have returned, without LIMIT (or an offset).
This is probably not as fast as your original query would be in isolation, but should be slightly faster than SELECT COUNT(...) ... followed by your original query. With small data sets, though, any differences will likely be below measurable limits.
See also https://dev.mysql.com/doc/refman/5.7/en/information-functions.html
You can also combine these things into a stored procedure that accepts items per page and page number, and returns all of the records along with metadata items such as the total number of pages.
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."'> [".$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 $counter :
Next
I am trying to create a page number function that displays 9 results per page from my forum_replies.sql table. My PHP code so far will only display page 1, page 2. Page 1 has 9 query's but page two has none... but there's 22 rows of data that should be fetched, so at least 2 pages should show!
Here's my code!
if(isset($_GET["p"]) && is_numeric($_GET["p"]) && $_GET["p"] > 1) {
$currentPage = $_GET["p"];
$limiter = $currentPage * 9;
} else {
$currentPage = 1;
$limiter = 0;
}
$finalQuery = "SELECT * FROM forum_replies WHERE thread_id = '1' ORDER BY id ASC LIMIT " . $limiter . ",9";
Figured out that the isset at the top.. $limiter works like this
0,9 = page 1.. correct
18,9 = page 3.. how do I get page 2 (9,9) and so on.. cause it's completely skipping 9,9!
How about calling echo $db->error; after each query? You can also echo the querys and try them in phpMyAdmin to find out what's wrong. I can't spot a mistake in the finalQuery, at least not syntax-wise.
Is it possible to create pagination without getting all elements of table?
But with pages in GET like /1 /666…
It usually involves issuing two queries: one to get your "slice" of the result set, and one to get the total number of records. From there, you can work out how many pages you have and build pagination accordingly.
A simply example:
<?php
$where = ""; // your WHERE clause would go in here
$batch = 10; // how many results to show at any one time
$page = (intval($_GET['page']) > 0) ? intval($_GET['page']) : 1;
$start = $page-1/$batch;
$pages = ceil($total/$batch);
$sql = "SELECT COUNT(*) AS total FROM tbl $where";
$res = mysql_query($sql);
$row = mysql_fetch_assoc($res);
$total = $row['total'];
// start pagination
$paging = '<p class="paging">Pages:';
for ($i=1; $i <= $pages; $i++) {
if ($i==$page) {
$paging.= sprintf(' <span class="current">%d</a>', $i);
} else {
$paging.= sprintf(' %1$d', $i);
}
}
$paging.= sprintf' (%d total; showing %d to %d)', $total, $start+1, min($total, $start+$batch));
And then to see your pagination links:
...
// loop over result set here
// render pagination links
echo $paging;
I hope this helps.
Yes, using mySQL's LIMIT clause. Most pagination tutorials make good examples of how to use it.
See these questions for further links and information:
How do you implement pagination in PHP?
Searching for advanced php/mysql pagination script
more results
You can use LIMIT to paginate over your result set.
SELECT * FROM comments WHERE post_id = 1 LIMIT 5, 10
where LIMIT 5 means 5 comments and 10 is the offset. You can also use the longer syntax:
... LIMIT 5 OFFSET 10
everyone. I am working on a site with smarty templates using php and a mysql database.
This is a more specific question than my first one which asked how to pass methods to a class. I thought it would be easier to repackage the question than edit the old one.
I have written a paginator script for my image gallery which displays images on the page. If a user has selected a category then only images in a particular category are shown and the results are always paginated.
The script is shown below.
$page_num = (isset($_GET['page_num']))?$_GET['page_num']:1; //if $_GET['page_num'] is set then assign to var $page_num. Otherwise set $page_num = 1 for first page
$category = (isset($_GET['req1']))?$_GET['req1']:'null'; //if $_GET['req1'] is set assign to $category other set $category to null
$items_pp = 5;
$total = $db->num_images_gallery($category); //returns the number of records in total('null') or in a particular category('category_name')
$pages_required = ceil($total/$items_pp); //total records / records to display per page rounded up
if($page_num > $pages_required){//in case the current page number is greater that the pages required then set it to the amount of pages required
$page_num = $pages_required;
}
if($page_num < 1){//in case the current page num is set to less that one set it back to 1
$page_num = 1;
}
$limit = "LIMIT " .($page_num - 1)*$items_pp . "," . $items_pp . ""; //if 5 results pre page and we on page 3 then LIMIT 10,5 that is record 10,11,12,13 and 14
$result = $db->get_images_gallery($category,$limit);
$i = 0;
while($row = $result->fetch_assoc()){
$images[$i]['file'] =$row['file'];
$images[$i]['file_thumb'] = str_replace('.','_thumbnail.',$row['file']);//show the thumbnail version of the image on the page
$images[$i]['title'] = $row['title'];
$images[$i]['description'] = $row['description'];
$i++;
}
if(!empty($images)){
$smarty->assign('images',$images);}else{
$smarty->assign('message',"There are no images to display in the ".ucwords(str_replace('_',' ',$category))." category");}
if($total > 0 && $pages_required >= 1){//only display this navigation if there are images to display and more than one page
$smarty->assign('page_scroll',$page_num . ' of ' . $pages_required);
$page_scroll_first = "<a href='".$_SERVER['REDIRECT_URL'] . "?page_num=1"."' >FIRST</a> <a href='".$_SERVER['REDIRECT_URL'] . "?page_num=" . ($page_num-1)."' ><<PREVIOUS</a>";
$page_scroll_last = " <a href='".$_SERVER['REDIRECT_URL'] . "?page_num=". ($page_num+1) . "'>NEXT>></a> <a href='" . $_SERVER['REDIRECT_URL'] . "?page_num=".$pages_required."'>LAST</a>";
if($page_num == 1){$page_scroll_first = "FIRST <<PREVIOUS";}
if($page_num == $pages_required){$page_scroll_last = "NEXT>> LAST";}
$smarty->assign('page_scroll_first',$page_scroll_first);//just use if statements to set the values for page scroll first and page scroll last and then assign them here
$smarty->assign('page_scroll_last',$page_scroll_last);
$smarty->assign('page_num',$page_num);
}
The script calls on two methods from my database class:
$db->num_images_gallery which looks like this:
function num_images_gallery($cat='null'){
$query = ($cat == 'null')?
"SELECT COUNT(*) AS images FROM images
LEFT JOIN image_categories ON (images.image_categories_id = image_categories.id)
WHERE images.gallery='1' AND image_categories.gallery = '1'"//no images should be shown in a category which is not intended to be shown at all
:
"SELECT COUNT(*) AS images FROM images
LEFT JOIN image_categories ON (images.image_categories_id = image_categories.id)
WHERE category = '{$cat}'
AND images.gallery='1' AND image_categories.gallery = '1'";
$result = $this->connection->query('SELECT COUNT(*) AS images FROM (?)',$x);
$row = $result->fetch_assoc();
$row_count = $row['images'];
echo $row_count;
return $row_count;
}
and the method $db::get_images_gallery() which looks like this:
function get_images_gallery($category,$limit){
$query = ($category=='null')?
"SELECT `file`,title,images.description,sizes,images.gallery,category FROM images
LEFT JOIN image_categories ON (images.image_categories_id = image_categories.id) WHERE images.gallery='1' AND image_categories.gallery = '1' {$limit}"
:
"SELECT `file`,title,images.description,sizes,images.gallery,category FROM images
LEFT JOIN image_categories ON (images.image_categories_id = image_categories.id)
WHERE category = '{$category}' AND images.gallery='1' AND image_categories.gallery = '1' {$limit}";
$result = $this->connection->query($query);
return $result;
}
I now want to create a class called paginate and put this script in it so i can display my site products paginated.
The main problem is that i need to use different functions to get the num of prodducts in my product table and then return the paginated results. How do i turn the script above into a class where i can change the functions which are used. I almost got an answer on my previous question, but the question was not specific enough.
Thanks
andrew
There's a Smarty Add-On for pagination.
You can find it here: http://www.phpinsider.com/php/code/SmartyPaginate/
For a quick example, extracted from the linked page:
index.php
session_start();
require('Smarty.class.php');
require('SmartyPaginate.class.php');
$smarty =& new Smarty;
// required connect
SmartyPaginate::connect();
// set items per page
SmartyPaginate::setLimit(25);
// assign your db results to the template
$smarty->assign('results', get_db_results());
// assign {$paginate} var
SmartyPaginate::assign($smarty);
// display results
$smarty->display('index.tpl');
function get_db_results() {
// normally you would have an SQL query here,
// for this example we fabricate a 100 item array
// (emulating a table with 100 records)
// and slice out our pagination range
// (emulating a LIMIT X,Y MySQL clause)
$_data = range(1,100);
SmartyPaginate::setTotal(count($_data));
return array_slice($_data, SmartyPaginate::getCurrentIndex(),
SmartyPaginate::getLimit());
}
index.tpl
{* display pagination header *}
Items {$paginate.first}-{$paginate.last} out of {$paginate.total} displayed.
{* display results *}
{section name=res loop=$results}
{$results[res]}
{/section}
{* display pagination info *}
{paginate_prev} {paginate_middle} {paginate_next}
Regarding your question about mixing the DB class and the Paginator class, it's all ok:
Your DB class will handle fetching data from DB
The SmartyPaginate class will handle the pagination
And your index.php just make the calls to each one where appropriate to set things out.
The idea is to keep responsibilities isolated.
Your DB class won't handle pagination, nor will your pagination class contain DB code.
From your other question, I think you were trying to do something too much convoluted for the problem at hand.
I'd suggest you to move all code that is DB-related inside your DB handling class and outside your index.php
This, for example:
$limit = "LIMIT " .($page_num - 1)*$items_pp . "," . $items_pp . ""; //if 5 results pre page and we on page 3 then LIMIT 10,5 that is record 10,11,12,13 and 14
This is DB logic, it generates (part of) an SQL string, so move it around.
It depends on 2 parameters, so find a way to get them available.
In this case, I'd suggest just passing both as parameters.
Instead of:
$result = $db->get_images_gallery($category,$limit);
Use:
$result = $db->get_images_gallery($category,$no_items, $page);
Also, your pager navigation rule should be inside your paginator class..
if($total > 0 && $pages_required >= 1){//only display this navigation if there are images to display and more than one page
$smarty->assign('page_scroll',$page_num . ' of ' . $pages_required);
$page_scroll_first = "<a href='".$_SERVER['REDIRECT_URL'] . "?page_num=1"."' >FIRST</a> <a href='".$_SERVER['REDIRECT_URL'] . "?page_num=" . ($page_num-1)."' ><<PREVIOUS</a>";
$page_scroll_last = " <a href='".$_SERVER['REDIRECT_URL'] . "?page_num=". ($page_num+1) . "'>NEXT>></a> <a href='" . $_SERVER['REDIRECT_URL'] . "?page_num=".$pages_required."'>LAST</a>";
if($page_num == 1){$page_scroll_first = "FIRST <<PREVIOUS";}
if($page_num == $pages_required){$page_scroll_last = "NEXT>> LAST";}
$smarty->assign('page_scroll_first',$page_scroll_first);//just use if statements to set the values for page scroll first and page scroll last and then assign them here
$smarty->assign('page_scroll_last',$page_scroll_last);
$smarty->assign('page_num',$page_num);
}
In this case, I hope the Add-On will handle it automatically for you.
You could then move this whole block, which does all your logic for fetching and preparing images data to a function (inside your ImageGalery class if you have one)
$total = $db->num_images_gallery($category); //returns the number of records in total('null') or in a particular category('category_name')
$pages_required = ceil($total/$items_pp); //total records / records to display per page rounded up
if($page_num > $pages_required){//in case the current page number is greater that the pages required then set it to the amount of pages required
$page_num = $pages_required;
}
if($page_num < 1){//in case the current page num is set to less that one set it back to 1
$page_num = 1;
}
$limit = "LIMIT " .($page_num - 1)*$items_pp . "," . $items_pp . ""; //if 5 results pre page and we on page 3 then LIMIT 10,5 that is record 10,11,12,13 and 14
$result = $db->get_images_gallery($category,$limit);
$i = 0;
while($row = $result->fetch_assoc()){
$images[$i]['file'] =$row['file'];
$images[$i]['file_thumb'] = str_replace('.','_thumbnail.',$row['file']);//show the thumbnail version of the image on the page
$images[$i]['title'] = $row['title'];
$images[$i]['description'] = $row['description'];
$i++;
}
Finally, on your index.php, all you have to do is:
Validate the parameters you received
Call your ImageGalery class to fetch the galery data (pass the parameters it needs)
Call your Pagination class to do the pagination (setting up navigation links, etc)
Set the Smarty template variables you need
And display it.
There is still lots of room for improvement, but I hope those few steps will help get your Image Galery code more clear.