Maybe you are looking for
coalesce(EndDate,datetime('now'))
This will pretend that a NULL EndDate is always seen as the 'current datetime'.
And you can find those records that need acting upon by the constraint EndDate
IS NULL, run whenever your application feels like it needs to "do something".
Note that the notion of 'current datetime' remains constant only within a
single call of sqlite3_step()
-----Ursprüngliche Nachricht-----
Von: sqlite-users [mailto:sqlite-users-boun...@mailinglists.sqlite.org] Im
Auftrag von GB
Gesendet: Donnerstag, 09. August 2018 08:47
An: sqlite-users@mailinglists.sqlite.org
Betreff: [EXTERNAL] Re: [sqlite] Can date('now') fire a trigger automatically
after a day passed?
That would require some sort of active process or cron job. But that's out of
scope of SQLite. You will have to implement that on your own.
But if your EndDate is always "now", why having a true column at all? If you do
not want to take the current date from your environment, how about something
like this:
select *, datetime("now") as EndDate from mytable
No process, no cron job required. And your EndDate will always be "now".
> Hi,
>
> I have a column in a table where a value in a row is 'now'.
> The 'now' value is in 'EndDate' column of that row.
> I have also a trigger which fire up when in the 'EndDate' column a
> Field was updated.
>
> Because the 'now' value does changing every day in sense that every
> one know that that yesterday's date is not equal with today's date I
> am thinking about that that this could be used to fire up that trigger
> automatically every day. But this does not work.
>
> Then is there a mechanism which would update automatically such date
> value - which is now the 'now' value in that 'EndDate' column Field
> after a day passed?
>
> This is needed in my application which calculates service time between
> two dates, namely between StartDate and EndDate where EndDate has the
> 'now' value.
>
> I hope I was clear what I mean.
>
> --
> Best, Pali
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> sqlite-users@mailinglists.sqlite.org
> http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
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