Comments on: Oracle Data Types – 5 FAQs About Number

By: Ben

Ben — Fri, 18 Sep 2009 22:09:20 +0000

p.s. I can’t post here from Firefox, it tells me I failed math

p.p.s. In my previous post, the middle argument to the lpad should be the desired length (I formatted in angle brackets so it got swallowed).

By: Ben

Ben — Fri, 18 Sep 2009 22:02:36 +0000

If ’001′ and ’00001′ represent different accounts, in my opinion it should be called an “account code” or “account id” rather than “account number”, given that it’s not a number.

Also, if you don’t want alphabetic characters to appear in your account numbers but you store as varchar, you really should be adding an additional check constraint, which is a pain if what you really want is a number.

If I had account numbers that really were numeric, but I wanted to format with leading zeros in some contexts, I’d store them as number and do lpad(accountnumber, , ’0′), perhaps in a calculated column.

Cheers,
Ben

By: pras99

pras99 — Tue, 17 Mar 2009 16:41:54 +0000

Hello, what is better for a primary key column, for example table departments with primary key dep_id? varchar or number????

What you advice me??

pd: I’m newbie in Oracle DB.

By: Lewi

Lewi — Sun, 15 Mar 2009 16:16:57 +0000

JT,

I completely disagree with that though. If you aren’t doing math, why are you trimming 0′s? The fact that the value has leading zeroes means that it is part of the data.

Account numbers have leading zeroes. An account number with 3 leading zeroes is different that one with 2 leading zeroes. If it were stored as a number, they would appear to be the same.

I have run into exactly that situation where the modeler decided to create account numbers as number because they were numeric. We had to retrofit varchar2 all over the place.

I stand by that: if you aren’t doing math, don’t store it as a number.

Thanks for the comment.

LewisC

By: Oracle Data Types - 5 FAQs About Number | Database Geek Blog

Oracle Data Types - 5 FAQs About Number | Database Geek Blog — Fri, 13 Mar 2009 16:34:46 +0000

[...] Oracle Data Types – 5 FAQs About Number | Database Geek Blog [...]

By: JT

JT — Fri, 13 Mar 2009 16:19:07 +0000

I don’t think I agree with this part in the last Q “If you are not doing math (or if the values are not used as mathematical values), store the value in a VARCHAR2.”

If its a number, store it as a number. Period. Otherwise you get stuff like 1, 0001, 0000001, etc.

Then you get developers asking why they’re getting a full table scan on select * from foo where trim(leading ’0′ from a) = 1

Treating numbers as strings almost always leads to headaches later.

My only gripe – Good info!