Weighted values...

[youradds]

Just wondering...does anyone know of a good way to execute a SQL query, with the values weighted. At the moment I am using RAND(), but I'm trying to get it so that I can add weights to the links, to get higher showing of some adverts than others.

i.e

Link 1 - weight 1
Link 2 - weight 4
Link 3 - weight 1
Link 4 - weight 2
Link 5 - weight 1

So link 2 would be shown 4 times more than link 2 (approx), and link 4 would be shown 2 times more than link 5, but 1/2 the amount of link 2.

Anyone got any suggestions?

Cheers

Andy

 

[BB101]

You could:

Get a random number from 1 to total of all weights,
Loop through each row adding the weights until you go past your number and take that result.

It's not a nice or fast way of doing it, but it's a way of doing it --BB

 

[skiflyer]

Here's a restatement with example.

So you assign 5 records 5 weights.

1 => 1
2 => 1
3 => 1
4 => 2
5 => 5
Sum= 10

Generate a random number from 0,9 (or 1-10 and replace greater than with equal to)

Now, loop through the rows summing their weights, when your sum is greater than the random number, grab that line.

Random # => Line showed
0=> 1
1=> 2
2=> 3
3=> 4
4=> 4
5=> 5
6=> 5
7=> 5
8=> 5
9=> 5


-Rob

 

[youradds]

Ah...I get you now

Thanks for the info...I'll give that a go with some code.

Cheers again.

Andy