UDF - fnIsLuhnValid by Peso

What is Luhn?

Luhn Algorithm written by Peso.

Get started:

Lets see how it works with @Luhn = 123455

First Loop

Second Loop

Third Loop

Fourth Loop

Fifth Loop

Sixth Loop (Last Index)

Finally, check @Sum can be modules by 10, if can, that means that the value is valid luhn number.

Reference

http://www.sqlteam.com/forums/topic.asp?TOPIC_ID=76195