Re: Unable To Alter Data Type

On Jan 11, 2012, at 19:30, Carlos Mennens <carlos.mennens@gmail.com> wrote:

> On Wed, Jan 11, 2012 at 7:13 PM, David Johnston <polobo@yahoo.com> wrote:
>> However, I will say again, you DO NOT WANT TO ACTUALLY DO THIS!
>>
>> The specific issue is that some US Postal Code begin with a zero ( 0 ) and
>> so whenever you want to the zip_code value you need to pad leading zeros if
>> the length is less than 5.  Now consider that a full zip_code can be in 5+4
>> format with an embedded hyphen and you no longer can even store it as
>> numeric.  If you deal with Canada (and maybe Mexico) at all then spaces and
>> letters become acceptable characters within the zip_code.
>
> David - Thank you for that great info / explanation. Very informative
> and helpful. I was not required to make this change but rather just
> goofing off attempting to learn SQL as I'm rather terrible at it. Can
> you tell me if there's an organized cheat sheet or something
> documented in regards to data types commonly used for commonly used
> field association? I think that's great for people who can't look at
> the documentation and clearly understand specific definitions or
> assumed categorization based on the type definition.

If you can perform reasonable arithmetic on the field value you encode it as a number otherwise  you should use text;
evenif the only possibly valid values are numbers. 

David J.