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Initial import of project, including new helper function for removing
everything before the primary FROM in the SQL query
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‎README.md

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# PHP Pagination Class
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Based off my original "Making Pagination Easier" blog post (http://www.michaelpeacock.co.uk/blog/entry/making-pagination-easier-with-php-class), however it has been altered to adjust the query so that the total count can be calculated by querying for a single row with a count included.
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## Usage
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<?php
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require_once('pagination.class.php');
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// establish a database connection in your code
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$db = mysqli_connect( 'localhost', 'root', '', 'database');
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// create the pagination object, and pass the database connection
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$p = new Pagination( $db );
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// set a limit
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$p->setLimit(3);
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// set an offset
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$p->setOffset( isset( $_GET['page_number'] ) ? intval( $_GET['page_number'] ) : 0 );
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// set the query
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$p->setQuery( "SELECT * FROM something " );
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// do the pagination
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$p->generatePagination();
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// what we do with these variables depends on the tempLating system used: the pagination object could send them direct to the template system for us
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// get an array of results
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$results = $p->getResults();
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// get the current page number
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$current_page = $p->getCurrentPage();
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// get the number of pages
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$number_of_pages = $p->getNumPages();
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$first_page_link = $p->isFirst() ? "" : "<a href='?page_number=0'>First page</a>";
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$previous_page_link = $p->isFirst() ? "" : "<a href='?page_number=".( $p->getCurrentPage() - 2 )."'>Previous page</a>";
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$next_page_link = $p->isLast() ? "" : "<a href='?page_number=" . $p->getCurrentPage() . "'>Next page</a>";
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$last_page_link = $p->isLast() ? "" : "<a href='?page_number=".( $p->getCurrentPage() - 1 )."'>Last page</a>";
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echo '<ul>';
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foreach( $results as $result )
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{
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echo '<li>' . $result['something'] . '</li>';
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}
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echo '</ul>';
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echo 'Page ' . $current_page . ' of ' . $number_of_pages . '<br />';
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echo $first_page_link . ' ' . $previous_page_link . ' ' . $next_page_link . ' ' . $last_page_link;
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?>

‎pagination.class.php

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<?php
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/**
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* Pagination class
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* Making pagination of records easy(ier)
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* @author Michael Peacock
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* @url www.michaelpeacock.co.uk
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*/
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class Pagination {
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/**
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* MySQLi Connection
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*/
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private $db;
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/**
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* The query we will be paginating
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*/
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private $query = "";
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/**
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* The processed query which will be executed
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*/
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private $executedQuery = "";
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/**
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* The results from the query
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*/
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private $results;
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/**
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* The maximum number of results to display per page
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*/
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private $limit = 25;
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/**
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* The results offset - i.e. page we are on (-1)
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*/
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private $offset = 0;
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/**
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* The number of rows there were in the query passed
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*/
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private $numRows;
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/**
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* The number of rows on the current page (main use if on last page, may not have as many as limit on the page)
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*/
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private $numRowsPage;
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/**
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* Number of pages of results there are
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*/
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private $numPages;
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/**
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* Is this the first page of results?
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*/
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private $isFirst;
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/**
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* Is this the last page of results?
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*/
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private $isLast;
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/**
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* The current page we are on
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*/
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private $currentPage;
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/**
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* Our constructor
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* @param mysqli $mysqli_link
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* @return void
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*/
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function __construct( $mysqli_link )
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{
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$this->db = $mysqli_link;
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}
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/**
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* Process the query, and set the paginated properties
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* @return bool (true if there are some rows on the page, false if there are not)
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*/
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public function generatePagination()
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{
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$temp_query = $this->query;
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// its more efficient to query one row (if possible) and include a count, as opposed to querying all of them
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if( preg_match( '#SELECT DISTINCT((.+?)),#si', $temp_query ) > 0 )
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{
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// this is a distinct query, we really have to query them all :-(
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$q = mysqli_query( $this->db, $temp_query );
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$nums = mysqli_num_rows( $q );
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$this->numRows = $nums;
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}
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else
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{
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// normal query, let's strip out everything before the "primary" FROM
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$q = mysqli_query( $this->db, "SELECT COUNT(*) AS nums " . $this->excludePrimarySelects( $temp_query ) . " LIMIT 1" );
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if( mysqli_num_rows( $q ) == 1 )
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{
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// how many rows?
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$row = mysqli_fetch_array( $q, MYSQLI_ASSOC );
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$this->numRows = $row['nums'];
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}
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else
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{
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// query didn't work...0 rows
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$this->numRows = 0;
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}
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}
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// limit!
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$this->executedQuery = $temp_query . " LIMIT " . ( $this->offset * $this->limit ) . ", " . $this->limit;
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$q = mysqli_query( $this->db, $this->executedQuery );
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while( $row = mysqli_fetch_array( $q, MYSQLI_ASSOC ) )
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{
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$this->results[] = $row;
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}
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// be nice...do some calculations
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// num pages
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$this->numPages = ceil($this->numRows / $this->limit);
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// is first
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$this->isFirst = ( $this->offset == 0 ) ? true : false;
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// is last
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$this->isLast = ( ( $this->offset + 1 ) == $this->numPages ) ? true : false;
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// current page
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$this->currentPage = ( $this->numPages == 0 ) ? 0 : $this->offset +1;
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$this->numRowsPage = mysqli_num_rows( $q );
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return ( $this->numRowsPage == 0 ) ? false : true;
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}
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//===========================================================================//
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// HELPER METHODS //
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//===========================================================================//
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/**
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* Exclude the primary selects from the SQL query
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* @param String $sql the SQL query
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* @return String the query starting with FROM
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*/
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private function excludePrimarySelects( $sql )
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{
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$word = "from";
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$wordLength = strlen( $word );
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$left = 0;
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$right = 0;
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$within = 0;
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$precedingSQLStatement = "";
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for( $i = 0; $i < ( strlen( $sql ) ); $i++ )
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{
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$left = ( $sql[ $i ] == "(" ) ? $left+1 : $left;
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$right = ( $sql[ $i ] == ")" ) ? $right+1 : $right;
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if( $left === $right )
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{
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if( $within < $wordLength && strcasecmp( $sql[ $i ], $word[ $within ] ) == 0 )
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{
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$within++;
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}
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elseif( $within <> $wordLength )
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{
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$within = 0;
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}
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}
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elseif( $within <> $wordLength )
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{
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$within = 0;
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}
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if( $within < $wordLength )
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{
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$precedingSQLStatement .= $sql[ $i ];
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}
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elseif( $within == $wordLength )
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{
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$precedingSQLStatement .= $sql[ $i ];
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break;
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}
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}
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return str_replace( $precedingSQLStatement, " FROM ", $sql );
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}
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//===========================================================================//
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// GETTER AND SETTER METHODS //
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//===========================================================================//
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/**
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* Set the query to be paginated
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* @param String $sql the query
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* @return void
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*/
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public function setQuery( $sql )
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{
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$this->query = $sql;
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}
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/**
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* Set the limit of how many results should be displayed per page
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* @param int $limit the limit
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* @return void
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*/
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public function setLimit( $limit )
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{
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$this->limit = $limit;
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}
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/**
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* Set the offset - i.e. if offset is 1, then we show the next page of results
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* @param int $offset the offset
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* @return void
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*/
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public function setOffset( $offset )
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{
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$this->offset = $offset;
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}
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/**
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* Get the result set
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* @return array
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*/
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public function getResults()
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{
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return $this->results;
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}
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/**
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* Get the number of pages of results there are
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* @return int
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*/
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public function getNumPages()
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{
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return $this->numPages;
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}
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/**
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* Is this page the first page of results?
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* @return bool
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*/
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public function isFirst()
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{
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return $this->isFirst;
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}
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/**
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* Is this page the last page of results?
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* @return bool
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*/
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public function isLast()
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{
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return $this->isLast;
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}
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/**
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* Get the current page within the paginated results we are viewing
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* @return int
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*/
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public function getCurrentPage()
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{
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return $this->currentPage;
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}
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/**
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* Get the number of rows there are on the current page
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* @return int
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*/
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public function getNumRowsPage()
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{
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return $this->numRowsPage;
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}
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}
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?>

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