如何对从该查询中获得的结果进行分页？

Question

该查询正在从数据库中提取结果，但是有太多结果导致页面挂起，是否可以对结果进行分页？

<?php $results = $wpdb->get_results("SELECT * FROM ns_light WHERE    donation_id != 0 AND light_date BETWEEN '2015-02-01' AND '2016-01-31' ORDER BY light_date DESC", OBJECT) ?>

<?php foreach ( $results as $l ) : ?>

<?php include('single-light-loop.php') ?>

<?php endforeach ?>

Answer 1

如果您使用的是MYSQL，则非常简单。

<?php 
$pag   = $_GET['p'];
$limit = 10; // how many rows per page?
$pag  *= $limit
if(empty($pag)){$pag=1}
?>
<?php $results = $wpdb->get_results("SELECT * FROM ns_light WHERE    donation_id != 0 AND light_date BETWEEN '2015-02-01' AND '2016-01-31' ORDER BY light_date DESC LIMIT ".$pag.",".$limit, OBJECT) ?>

<?php foreach ( $results as $l ) : ?>

<?php include('single-light-loop.php') ?>

<?php endforeach ?>

Answer 2

如果不进行测试，则可以按照以下方式尝试一些操作。

/* Number of records per page */
$maxRows=10;

/* The total number of expected rows: uses db result 'dbrecordcount' */
$totalRows=$db->dbrecordcount;

/* Current page within paged results: retrieve `page` from querystring if using GET method */
$pageNumber=$_GET['page'];

/* How many pages of results are there */
$totalPages=( $maxRows > 0 ) ? abs( ceil( $totalRows / $maxRows ) - 1 ) : 0;

/* Where does paging begin */
$startRow=$pageNumber * $maxRows;



$sql="select 
    ( select count(*) from `ns_light` where `donation_id` != 0 and `light_date` between '2015-02-01' and '2016-01-31' ) as 'dbrecords', 
    * from `ns_light` 
    where `donation_id` != 0 and `light_date` between '2015-02-01' and '2016-01-31' 
    order by `light_date` desc
    limit $startRow, $maxRows;"




/* Display pagination links if there are sufficient number of records */
if( $totalPages > 0 && $totalRows > $maxRows ){

    /* First record link */
    if( $pageNumber==0 ) {
        echo "First";
    } else {
        echo "<a href='?page=0'>First</a>";
    }

    /* Previous record link */
    if( $pageNumber > 0 ){
        echo "<a href='?page=".max( 0, $pageNumber - 1 )."'>Previous</a>";
    } else {
        echo "Previous";
    }

    /* Next record link */
    if( ( $pageNumber + 1 ) > $totalPages ){
        echo 'Next';
    } else {
        echo "<a href='?page=".min( $totalPages, $pageNumber + 1 )."'>Next</a>";
    }

    /* Last record link */
    if( $pageNumber==$totalPages ){
        echo 'Last';
    } else {
        echo "<a href='?page=".$totalPages."'>Last</a>";
    }
}