1. How do you add rating to the user
Insert a row with the user ID being the ID of the user being rated and the rating as an integer ranging from 1-5. Individual database structures will vary, but that is the basic idea.

2. If I rate someone as 3 of 5, then what will be inserted into db?
A value of 3 and the ID of the user

3. And also, how do you count how many ppl have rated?
How many people have submitted a rating? You would have to add a column that contains the ID of the person who rated the person and write a query to count the distinct user IDs.

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