Now when I connect to a link like: example.com/tags/some-thing I want to get all posts & news have tag with slug some-thing via table tag_datas and order by posteddate.
With one table posts or news, It’s very easy with relation. Any solutions for me?
I suggest to use single table inheritance for posts and news table. Look at this link. Why do you have column "slug" in posts/news and also in tags? You have join table "tag_datas", so you can use it to get all posts for given slug.