我在这里测试了两个表的左连接查询，SQL语句是：
select a.blog_id,a.blog_title,a.blog_thumb,a.blog_click,a.blog_addtime,a.blog_show,b.blog_category_name from `think_blog` a left join `think_blog_category` b on a.blog_category_id=b.blog_category_id where 1 order by blog_addtime desc limit 0,100select a.blog_id,a.b
