PHP, 5 Star Rating System (Logic only)

[keldorn]

What the logic behind those 5 Star rating things you seee on youtube,

Is it just division? , like if someone votes  5, then store 5 in the DB, then if someone votes 2, divided 5 by 2, so you get 2.5 then round() it to 3, Then show 3 stars, is that all there is too it?

 

Edit; oh what if the rating is 3, now someone votes 5? You can't divided 3 by 5.

[Psycho]

What the logic behind those 5 Star rating things you seee on youtube,

Is it just division? , like if someone votes  5, then store 5 in the DB, then if someone votes 2, divided 5 by 2, so you get 2.5 then round() it to 3, Then show 3 stars, is that all there is too it?

 

What? How do you get a rating of two would display three stars? It's simply an average. You simply add up ALL the ratings and divide by the number (i.e. count) of ratings to get the average. Then round as needed.

 

Ex:

 

Ratings of 3, 4, 3, 2, 1, 5, 2

 

Sum = 20

Count = 7

 

Average = ( 20 / 7 ) = 2.86

Rounds to 3

[keldorn]

oh, Okay.

What would be the way to store the numbers in the row, serialize() it?

 

 

Edit: Nevermind, I would  normalize the database and  make a separate table for the ratings, Then create two indexs called "Count" and "votes", and store each number there rather then storing all the votes like 1,5,8,4,2,1

 

So you could have

 

id+Vote+Count+
1   20       5
2   40       9
3   55       12

 

Then just increment them when needed, and divided when needed.