Question

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Rating System in PHP and MySQL

I am working on a rating system on a scale from 1 to 10. I want to be able to keep track of all users ratings and if they have already rated that particular item.

Notes:
-I have a log in so every user has a unique id in the database.
-Each particular item also has a unique id.

My question is: How should I store this information accurately in a database in the best possible manner.

This is how I am thinking of doing it:

Unique_Key | Item_ID | User_ID | User_rating
     1          1           1           (1-10)
     2          1           2           (1-10)
     3          2           2           (1-10)
     4          3           1           (1-10)
     5          4           1           (1-10)

So if the Item_ID a user is rating is already in the db with their User_ID they wont be able to rate, otherwise they can.

I am looking for suggestions if this is a safe, clean way to do this before I start any coding. Thank You.

Answer 1

If you add a unique key to your itemID – userID combination then this will be a save method to store that information.

You can add a unique key like this

ALTER TABLE your_table
ADD UNIQUE (itemID, userID);

The UNIQUE constraint uniquely identifies each record in a database table. The UNIQUE and PRIMARY KEY constraints both provide a guarantee for uniqueness for a column or set of columns.