How to get next ID on next page PHP - php

Question

I want to read the different ID on different page, by using the prev/next button.
If I click next button, I want to get the next ID, if I click previous button, it will back to the previous ID. Following is what I want.
Example:
testnext_pre1.php?id=1&page=1
testnext_pre1.php?id=2&page=2
testnext_pre1.php?id=5&page=3
Here is my problem. As you can see, I get the same ID on every page because of my code. How to get the correct ID for the page?
Please take note: the IDs are not increase by sequence, as some contents might be deleted. So I don't want the answer something like "+1".
$rowsPerPage = 1;
if(isset($_GET['page']))
{
$pageNum= $_GET['page'];
}
else
{
$pageNum = 1;
}
// preceding rows
$previousRows =($pageNum - 1) * $rowsPerPage;
$query = "SELECT * FROM news LIMIT $previousRows, $rowsPerPage";
$result = mysql_query($query) or die('Error couldn\'t get the data').mysql_error();
echo "<table border=1>\n";
echo "<tr><th>ID</th><th>Name</th><th>Password</th><th>Perm</th><th>Email</th>
<th>Date</th></tr>";
// print the results
while(list($id,$name,$pass,$perm,$email,$date) = mysql_fetch_array($result))
{
echo "<tr><td>$id</td><td>$name</td><td>$pass</td><td>$perm</td><td>$email</td>
<td>$date</td></tr>";
}
echo '</table>';
$query = "SELECT COUNT(id) AS numrows FROM news";
$result = mysql_query($query) or die('Error, couldn\'t get count title=\"$page\"').mysql_error();
$row = mysql_fetch_assoc($result);
$numrows = $row['numrows'];
$lastPage = ceil($numrows/$rowsPerPage);
$phpself = $_SERVER['PHP_SELF'];
if ($pageNum > 1)
{
$page = $pageNum - 1;
$prev = "<div class=\"paginationbtn floatleft\">previous</div>";
$first = " [First Page] ";
}
else
{
$prev = ' previous ';
$first = ' [First Page] ';
}
if ($pageNum < $lastPage)
{
$page = $pageNum + 1;
$resultid = mysql_query("SELECT id FROM news");
while($loopid=mysql_fetch_array($resultid))
{
$rowid = $loopid['id'];
$next = " <div class=\"paginationbtn floatright\">next</div> ";
}
}
else
{
$next = ' [Next] ';
}
echo $prev . " " . $next;

Answer 1

Just get the previous and next ids from the database
if ($pageNum > 1)
{
//Get previous id using this query
SELECT id FROM news LIMIT $previousRows-1, $rowsPerPage
}
if ($pageNum < $lastPage)
{
//Get next id using this query
SELECT id FROM news LIMIT $previousRows+1, $rowsPerPage
}

Answer 2

Try the following sql query to get the next id,right now you are looping the news table and your next button will always have the same value
if ($pageNum < $lastPage)
{
$page = $pageNum + 1;
$resultid = mysql_query("select id from news where id = (select min(id) from news where id > ".$_GET['id'].")");
while($loopid=mysql_fetch_array($resultid))
{
$rowid = $loopid['id'];
$next = " <div class=\"paginationbtn floatright\">next</div> ";
}
$prevresultid = mysql_query("select id from news where id = (select max(id) from news where id < ".$_GET['id'].")");
while($loopid=mysql_fetch_array($prevresultid))
{
$rowid = $loopid['id'];
$prev= " <div class=\"paginationbtn floatleft\">next</div> ";
}
}
Note: you will need mysqli and prepared statements to secure your code

Answer 3

if you want to set pagination than no need of next id it will mange by query only . and in query we change only offset .
for e.g each page display 3 records so our limit is 3
now if we on first page than our fetch record query is(on first page offset is always 0)
so offset is 0 and limit is 3
SELECT fieldName FROM tableName LIMIT offset,limit
for second page now current offset is 3 so
prev is current_offset minus limit (3-3) so prev offset is 0
next is current_offset plus limit (3+3) so next offset is 6
now in 3rd page current offset is 6
prev is current_offset minus limit (6-3) so prev offset is 3
next is current_offset plus limit (6+3) so next offset is 9

Answer 4

try this one
<?php
$rowsPerPage = 1;
if(isset($_GET['page']))
{
$pageNum= $_GET['page'];
}
else
{
$pageNum = 1;
}
// preceding rows
$previousRows =($pageNum - 1) * $rowsPerPage;
$query = "SELECT * FROM news LIMIT $previousRows, $rowsPerPage";//offset,limit
$result = mysql_query($query) or die('Error couldn\'t get the data').mysql_error();
echo "<table border=1>\n";
echo "<tr><th>ID</th><th>Name</th><th>Password</th><th>Perm</th><th>Email</th>
<th>Date</th></tr>";
// print the results
while(list($id,$name,$pass,$perm,$email,$date) = mysql_fetch_array($result))
{
echo "<tr><td>$id</td><td>$name</td><td>$pass</td><td>$perm</td><td>$email</td>
<td>$date</td></tr>";
}
echo '</table>';
$query = "SELECT COUNT(id) AS numrows FROM news";
$result = mysql_query($query) or die('Error, couldn\'t get count title=\"$page\"').mysql_error();
$row = mysql_fetch_assoc($result);
$numrows = $row['numrows'];
$lastPage = ceil($numrows/$rowsPerPage);
$phpself = $_SERVER['PHP_SELF'];
if ($pageNum > 1)//current page > 1
{
$page = $pageNum - 1;
$prev = "<div class=\"paginationbtn floatleft\">previous</div>";
$first = " [First Page] ";
}
else
{
$prev = ' previous ';
$first = ' [First Page] ';
}
if ($pageNum < $lastPage)
{
$page = $pageNum + 1;
$next_row=$previousRows+1;
$resultid = mysql_query("SELECT id FROM news LIMIT $next_row,1");
while($loopid=mysql_fetch_array($resultid))
{
$rowid = $loopid['id'];
$next = " <div class=\"paginationbtn floatright\">next</div> ";
}
}
else
{
$next = ' [Next] ';
}
echo $prev . " " . $next;