how to keep track of visitor read and not read articles ?

quecoder

Hello
there are many applications like forums and email services that allow you to know if you have read this email or not, or emails that you have not read yet [inbox (XX) where XX is their number] or forums that shows you all threads you have not read from your last visit ...

how can they do that ... I mean , how this database is designed ? or do they use XML or other technologies !?

bretticus

There are a number of ways I'm sure. To name one would be to simply insert a database record each time a user views a specific forum post.

Piranha

I would use one of the following ways:

If you have content that only one user should be able to access, for example an email account, you add a column in the email indicating if it was read or not.
If you have content that many users could access, for example forum posts, you add a table between the user and the forum post table where you add a row when a user view the post.

quecoder

Piranha;10887005 wrote:
I would use one of the following ways:

If you have content that only one user should be able to access, for example an email account, you add a column in the email indicating if it was read or not.

If you have content that many users could access, for example forum posts, you add a table between the user and the forum post table where you add a row when a user view the post.

but there might be hundreds of thousands of columns for big forums , how much it will take to perform a search for 20 threads per page per user!..

Piranha

There may be yes. And if you have such a big forum you probably have a database server that can handle the load. And you have probably indexed the correct columns. And optimized the code. Databases are built for these kind of things.