Обсуждение: Adding timestamp column

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Adding timestamp column

От
Mauricio Fernandez
Дата:
Hi admins, greetings.

I'm trying to add a timestamp column in an existent table.

This query works fine:

select timecreated, timezone('America/Santiago'::text, to_timestamp(timecreated::double precision)) datecreated  
from MDL_LOGSTORE_STANDARD_LOG;

But, when I want to alter the table I get  a syntax error

alter table MDL_LOGSTORE_STANDARD_LOG
  add column datecreated timestamp
  generated always as ( timezone ('America/Santiago'::text, to_timestamp(timecreated::double precision)));

SQL Error [42601]: ERROR: syntax error at end of input
  Position: 185

I would appreciate some tips

Thanks in advanced

kind regards

Mauricio Fernández

Re: Adding timestamp column

От
"David G. Johnston"
Дата:
On Wednesday, September 3, 2025, Mauricio Fernandez <mmauricio.fernandez@gmail.com> wrote:

But, when I want to alter the table I get  a syntax error

alter table MDL_LOGSTORE_STANDARD_LOG
  add column datecreated timestamp
  generated always as ( timezone ('America/Santiago'::text, to_timestamp(timecreated::double precision)));

SQL Error [42601]: ERROR: syntax error at end of input
  Position: 185


Unless you are experimenting with v18 the docs clearly indicate the keyword “stored” is mandatory (since the implemented in 18 virtual is the default).

David J.
 

Re: Adding timestamp column

От
Holger Jakobs
Дата:
Am 03.09.25 um 17:50 schrieb Mauricio Fernandez:
> Hi admins, greetings.
>
> I'm trying to add a timestamp column in an existent table.
>
> This query works fine:
>
> select timecreated, timezone('America/Santiago'::text, 
> to_timestamp(timecreated::double precision)) datecreated
> from MDL_LOGSTORE_STANDARD_LOG;
>
> But, when I want to alter the table I get  a syntax error
>
> alter table MDL_LOGSTORE_STANDARD_LOG
>   add column datecreated timestamp
>   generated always as ( timezone ('America/Santiago'::text, 
> to_timestamp(timecreated::double precision)));
>
> SQL Error [42601]: ERROR: syntax error at end of input
>   Position: 185
>
> I would appreciate some tips
>
> Thanks in advanced
>
> kind regards
>
> Mauricio Fernández

Instead of

alter table MDL_LOGSTORE_STANDARD_LOG
   add column datecreated timestamp
   generated always as ( timezone ('America/Santiago'::text, 
to_timestamp(timecreated::double precision)));

I would suggest

ALTER TABLE MDL_LOGSTORE_STANDARD_LOG
ADD COLUMN datecreated TIMESTAMP
   GENERATED ALWAYS AS (timecreated AT TIME ZONE 'America/Santiago') STORED;

You didn't tell us the data type of the column timecreated. It should be 
'TIMESTAMPTZ DEFAULT current_timestamp' for it to work properly.

As of Version 18 you can leave out STORED, creating a virtual generated 
column.

Kind Regards,

Holger

-- 

Holger Jakobs, Bergisch Gladbach

Re: Adding timestamp column

От
Mauricio Fernandez
Дата:

Thank you Holger and David, the error was the missing clausule STORED

The timecreated data type is Int8

King regards

Mauricio Fernández

El mié, 3 sept 2025 a las 13:46, Holger Jakobs (<holger@jakobs.com>) escribió:
Am 03.09.25 um 17:50 schrieb Mauricio Fernandez:
> Hi admins, greetings.
>
> I'm trying to add a timestamp column in an existent table.
>
> This query works fine:
>
> select timecreated, timezone('America/Santiago'::text,
> to_timestamp(timecreated::double precision)) datecreated
> from MDL_LOGSTORE_STANDARD_LOG;
>
> But, when I want to alter the table I get  a syntax error
>
> alter table MDL_LOGSTORE_STANDARD_LOG
>   add column datecreated timestamp
>   generated always as ( timezone ('America/Santiago'::text,
> to_timestamp(timecreated::double precision)));
>
> SQL Error [42601]: ERROR: syntax error at end of input
>   Position: 185
>
> I would appreciate some tips
>
> Thanks in advanced
>
> kind regards
>
> Mauricio Fernández

Instead of

alter table MDL_LOGSTORE_STANDARD_LOG
   add column datecreated timestamp
   generated always as ( timezone ('America/Santiago'::text,
to_timestamp(timecreated::double precision)));

I would suggest

ALTER TABLE MDL_LOGSTORE_STANDARD_LOG
ADD COLUMN datecreated TIMESTAMP
   GENERATED ALWAYS AS (timecreated AT TIME ZONE 'America/Santiago') STORED;

You didn't tell us the data type of the column timecreated. It should be
'TIMESTAMPTZ DEFAULT current_timestamp' for it to work properly.

As of Version 18 you can leave out STORED, creating a virtual generated
column.

Kind Regards,

Holger

--

Holger Jakobs, Bergisch Gladbach