Thread: overwrite column data select - Postgres 9.2

I've got a table with email column:

email CHARACTER VARYING(50) DEFAULT ''::CHARACTER VARYING NOT NULL,

There are 30k rows and the email column is not null... there is data in there.

But for testing purpose I need to overwrite the email. So the customer won't get an email from me while testing code.

The email could be replaced by: test.UID@example.com

How can I do that?

-- 
john r pierce, recycling bits in santa cruz

>
> I was hopping that in a SELECT I could replace the data from the email
> column to something else...
>
>
> maybe email = name_first + name_last? Is that possible?
>
> I can't overwrite the data into that column... that has to be done by
> the select (if possible)

SELECT <item1>, <item2>, ..., name_first || ' ' || name_last AS email
FROM ...

You can't use SELECT *, you must list everything but email.

update table tablename set email = 'test.UID@example.com';     ?

I can't overwrite the data into that column...

I was hopping that in a SELECT I could replace the data from the email column to something else...

select 'test.UID@example.com' as email

-- 
john r pierce, recycling bits in santa cruz

> Hi guys,

> I've got a table with email column:
> email CHARACTER VARYING(50) DEFAULT ''::CHARACTER VARYING NOT NULL,

> There are 30k rows and the email column is not null... there is data in there.
> But for testing purpose I need to overwrite the email. So the customer won't get an email from me while testing code.

> The email could be replaced by: test.UID@example.com

> How can I do that?
> Thanks!
> Patrick

In my mind, that's not a DB issue but an application issue since Pg doesn't send email (or I haven't seen that ability
init). So change the application that does the sending and comment out the "send" call. If you don't have the source
forthe app and can't do that, then disable the sending part at the OS level; a good sys-admin should have no trouble
withthat (turning off sendmail or whatever). 

HTH,
Kevin

Hi Patrick.

----- Original Message -----
From: "Patrick B" <patrickbakerbr@gmail.com>
To: "pgsql-general" <pgsql-general@postgresql.org>
Sent: Wednesday, September 21, 2016 1:02 AM
Subject: [GENERAL] overwrite column data select - Postgres 9.2


> I've got a table with email column:
>
>> email CHARACTER VARYING(50) DEFAULT ''::CHARACTER VARYING NOT NULL,
>

An off-topic question.

Does your application explicitly restrict the length of email addresses
to 50 characters? Are you able to dictate an email address maximum
length of 50 characters? Or do you actually expect your application to
be able accept any valid email address from users?

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,

Disclosure: I'm a PG newbie (and a relative SQL newbie, too), and not
familiar with the DEFAULT ":: notation in your DDL.

Steve

>
> There are 30k rows and the email column is not null... there is data
> in
> there.
> But for testing purpose I need to overwrite the email. So the customer
> won't get an email from me while testing code.
>
> The email could be replaced by: test.UID@example.com
>
> How can I do that?
> Thanks!
> Patrick
>

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).
--
Jim Nasby, Data Architect, Blue Treble Consulting, Austin TX
Experts in Analytics, Data Architecture and PostgreSQL
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