WordPress添加底部页脚动态版权时间

原始实现代码

    //原始代码有缺陷，不推荐
    function comicpress_copyright() {
        global $wpdb;
        $copyright_dates = $wpdb->get_results(" 
    SELECT 
    YEAR(min(post_date_gmt)) AS firstdate, 
    YEAR(max(post_date_gmt)) AS lastdate 
    FROM 
    $wpdb->posts 
    WHERE 
    post_status = 'publish' 
    ");
        $output = '';
        if($copyright_dates) {
            $copyright = "© " . $copyright_dates[0]->firstdate;
            if($copyright_dates[0]->firstdate != $copyright_dates[0]->lastdate) {
                $copyright .= '-' . $copyright_dates[0]->lastdate;
            }
            $output = $copyright;
        }
        return $output;
    }

//原始代码有缺陷，不推荐

function comicpress_copyright() {

global $wpdb;

$copyright_dates = $wpdb->get_results("

SELECT

YEAR(min(post_date_gmt)) AS firstdate,

YEAR(max(post_date_gmt)) AS lastdate

FROM

$wpdb->posts

WHERE

post_status = 'publish'

");

$output = '';

if($copyright_dates) {

$copyright = "© " . $copyright_dates[0]->firstdate;

if($copyright_dates[0]->firstdate != $copyright_dates[0]->lastdate) {

$copyright .= '-' . $copyright_dates[0]->lastdate;

}

$output = $copyright;

}

return $output;

}

在需要显示版权的地方添加

<?php echo comicpress_copyright(); ?>

1	<?php echo comicpress_copyright(); ?>

这段代码是网上流传的形式，其实现原理：通过获取第一篇文章和最新发布文章的发布时间来确定年份，那么通过原理可知，代码缺点非常明显——依赖于发布体（如文章等post），夸张一下，你一年两年甚至三年都没有发布新文章，版权时间将会出现错误，因为代码的功能是根据你的文章来确定年份。

那么如何取消这种依赖性，让运营版权时间更准确呢？往下看

优化版代码

    //显示网站运营版权时间
    function auto_copyright() {
        global $wpdb;
        $first = $wpdb->get_results(" 
    SELECT user_registered
    FROM   $wpdb->users  
    ORDER BY  ID ASC 
    LIMIT 0,1
    ");
        $output = '';
        $current = date(Y) ;
        if($first) {
            $first=date(Y,strtotime($first[0]->user_registered));
            $copyright = "© " . $first;
            if($first != $current) {
                $copyright .= '-' .$current;
            }
            $output = $copyright;
        }
        echo  $output;
    }