Re: Detecting which columns a query will modify in a function calledby a trigger

On 3/3/20 9:42 AM, stan wrote:
> On Mon, Mar 02, 2020 at 01:44:52PM -0700, David G. Johnston wrote:
>> On Mon, Mar 2, 2020 at 1:28 PM stan <stanb@panix.com> wrote:
>>
>>> Envision a table with a good many columns. This table represents the "life
>>> history" of a part on a project. Some of the columns need to be
>>> created/modified by the engineer. Some need to be created/modified by the
>>> purchasing agent, some of the columns need to be created by the receiving
>>> department, some of the columns need to be created/modified by the accounts
>>> payable department.
>>>
>>> Make sense?
>>>
>>
>> On a theory level this design is insufficiently normalized.  The fact that
>> you are having issues and challenges working with it suggests you should
>> seriously consider a different design, one that exhibits better
>> normalization properties.
>>
>> Alternatively you might consider just removing direct access to the table
>> and provide views and/or functions that can use normal permission grants.
>> Add some check constraints to the table to describe and enforce the
>> inter-field relationships that are present.
>>
> 
> Thanks for the input.
> 
> I have, indeed created views that restrict the subset of columns that a
> particular job function needs access to to the appropriate ones, but
> unfortunately to the best of my knowledge, I cannot INSERT/UPDATE a table
> through a view.
> 
> Am I suffering from a lack of knowledge here?

Yes:

https://www.postgresql.org/docs/12/sql-createview.html

Updatable Views



-- 
Adrian Klaver
adrian.klaver@aklaver.com