I would do so, since the same news can be displayed on 2 or more sites:
Create a Sites table with the columns id (1, 2 and 3) and column url (website address, eg: www.meusite.com), then you insert the sites immediately.
After creating a pivot table Sites_Noticias since the relation is N: N (many news for many websites), this is the table that will relate Sites to Noticias . In this table I stored only two data, I created a column id_noticia and id_site
So this way you already have the news / news and the site / sites reviewed.
Now for ex:
Table Sites :
id | url
1 | www.meusite1.com
2 | www.meusite2.com
3 | www.meusite3.com
Table Sites_Noticias :
site_id | id_notice
1 | 3
2 | 1
1 | 2
3 | 1
In this example we can see that the news item whose id is 1 will appear on the site whose id is 2 (www.meusite2.com) and the site whose id is 3 (www.meusite3.com). In site 1 (www.meusite1.com) will be published the news with id's 3 and 2.
For the pivot table ( Sites_Noticias ), depending on the site where you are, you can go get the news (the Noticias table) that should be displayed. In this example if we have in site 1 we will get the news whose id's are id's 3 and 2.
SQL to fetch the news that is part of the www.meusite1.com site:
SELECT Noticias.* FROM Sites JOIN Sites_Noticias ON Sites.id = Sites_Noticias.id_site JOIN Noticias ON Noticias.id = Sites_Noticias.id_noticia WHERE Sites.url="www.meusite1.com";
I apologize for the poor formatting of the response, I tried to be as clear as possible.
