select FROM_UNIXTIME(pubtime, '%Y-%m') as pubtime, count(*) as cnt from articles group by FROM_UNIXTIME(pubtime, '%Y-%m') 

PHP文章按日期（日）SQL归档

 
select FROM_UNIXTIME(pubtime, '%Y-%m-%d') as pubtime, count(*) as cnt from articles group by FROM_UNIXTIME(pubtime, '%Y-%m-%d') 

非时间戳日期格式归档(date_format格式化日期)

 
select date_format(`post_date`,'%Y%m%d') as pubtime, count(*) as cnt from wp_posts where `post_status`='publish' group by date_format(`post_date`,'%Y%m%d') order by `ID` desc 
select date_format(`post_date`,'%Y%m%d') as pubtime,date_format(`post_date`,'%m 月 %d 日') as shijian,count(*) as cnt from wp_posts where `post_status`='publish' group by date_format(`post_date`,'%Y%m%d') order by `ID` desc limit 0,7