# Dumb migration question

**URL:** <https://www.ruby-forum.com/t/dumb-migration-question/131526>\
**Category:** Rails\
**Created:** [March 11, 2008, 12:15am UTC](https://www.ruby-forum.com/t/dumb-migration-question/131526 "2008-03-11T00:15:43Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![ron](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/ecae2f/32.png) [@ron](https://www.ruby-forum.com/u/ron)\
**Post date:** [March 11, 2008, 12:15am UTC](https://www.ruby-forum.com/t/dumb-migration-question/131526/1 "2008-03-11T00:15:43Z")

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Hi,

So this is a bit embarrassing, but I’ve been working through the depot  
tutorial in Agile Web D… In the add\_column migration, there  
is:

add\_column :products, :price, :decimal, :precision =\>  
8, :scale=\>2, :default=\>0

I’m assuming that precision means the number of significant digits,  
no? Could someone clarify what those three parameters after decimal  
mean?

Thanks,

Ron

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<div class="post-metadata">

**Author:** ![ron](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/ecae2f/32.png) [@ron](https://www.ruby-forum.com/u/ron)\
**Post date:** [March 11, 2008, 12:19am UTC](https://www.ruby-forum.com/t/dumb-migration-question/131526/2 "2008-03-11T00:19:15Z")

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Oops…sorry. I figured it out. precision is number of significant  
digits and scale just says that two are after the decimal point.

R