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03/05/2009 at 12:50AM PST, ID: 24200651
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9.3

Probability distribution using MySQL RAND() function

Asked by bobbit31 in Microsoft Office Suite, MySQL Server, Databases Miscellaneous

Tags: mysql RAND() probability

I am trying to right a FUNCTION in MySQL that will return a random value.  Here is the tricky part:

31 has 70% chance of being returned
32 has 20% chance of being returned
33 has 10% chance of being returned

I am basically gifting an item but its luxury value is random..

Hope someone could figure this out using RAND()

1:
2:
3:
4:
5:
6:
7:

Here is the only function in MySQL that would help but still doesnt give me a chance to set the probability:
 
 The effect of using a non-constant argument is undefined. As of MySQL 5.0.13, non-constant arguments are disallowed.
 
To obtain a random integer R in the range i <= R < j, use the expression FLOOR(i + RAND() * (j  i)). For example, to obtain a random integer in the range the range 7 <= R < 12, you could use the following statement:
 
SELECT FLOOR(7 + (RAND() * 5));
[+][-]03/05/09 02:19 AM, ID: 23804004

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Zones: Microsoft Office Suite, MySQL Server, Databases Miscellaneous
Tags: mysql RAND() probability
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Solution Provided By: StraySod
Participating Experts: 1
Solution Grade: A
 
 
 
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