Re: overwrite column data select - Postgres 9.2

2016-09-22 10:02 GMT+12:00 Jim Nasby <Jim(dot)Nasby(at)bluetreble(dot)com>:

> On 9/21/16 1:50 PM, Steve Petrie, P.Eng. wrote:
>
>>
>> The reason I ask is -- the maximum length of a valid email address is
>> actually 256 characters (or 254, according comments in the PHP function
>> is_valid_email_address(...) that I found on the Internet at
>> http://code.iamcal.com/ and use myself).
>>
>> In my own PG DDL, I define email addresses like:
>>
>> contact_email_addr varchar(256) NOT NULL,
>>
>
> FWIW, I stay away from varchar limits that are more than a "suggestion".
> Generally speaking it's just not worth limiting to something like 50, then
> the business decides they want 60, then 70, then... I still use varchar to
> ensure the database can't get DOS'd with garbage, but I'll just set
> something like varchar(100). That said, if there's a defined limit for
> email address length, might as well use it...
>
> Disclosure: I'm a PG newbie (and a relative SQL newbie, too), and not
>> familiar with the DEFAULT ":: notation in your DDL.
>>
>
> The :: is a cast that was presumably added by Postgres when the default
> was assigned. It's equivalent to DEFAULT ''. I definitely don't like
> defaults like that... if you don't know what the email is then it should be
> NULL. Or to put it another way, having a default set largely defeats the
> purpose of NOT NULL (IMHO).
> --
>
>

Rather than test(dot)UID(dot)(at)example(dot)com <test(dot)UID(dot)(at)tikcha(dot)com> I was hoping for
values such as:

test.4645364.@ <test(dot)4645364(dot)(at)tikcha(dot)com>example.com <test(dot)UID(dot)(at)tikcha(dot)com>

test.8786756.@ <test(dot)8786756(dot)(at)tikcha(dot)com>example.com <test(dot)UID(dot)(at)tikcha(dot)com>

With UNIQUE UUID

is that possible?

Cheers

Patrick