Database structure-How to determine if a new reply is available

Database structure--How to determine whether there is a new reply?
Database structure--How to determine whether there is a new reply?
If I posted here, people reply to my post, I entered the post center, this post will be highlighted, I click to browse this post, this post becomes ordinary non-highlighted state, what should the database structure be?

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Set a field:
The initial value is a
Reply plus one, browse minus one

List, you can judge

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Add a field in the table, increment on the line, there is a reply to add a
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Be a field, Update_time database set up, update, record the last update time!

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