DOES INFORMIX SUPPORT TIMESTAMP CONSTANT
Matthew Herbert asked whether Informix has a TIMESTAMP constant for detecting changed records. Art Kagel said there is no built-in per-row timestamp, but one can add a DATETIME YEAR TO FRACTION(3) DEFAULT CURRENT column, with an update trigger to maintain it on updates. Rudy Fernandes noted that CURRENT can be set in an UPDATE statement.
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Hi Does anyone know whether Informix supports the symbolic constant TIMESTAMP for individual records. I am trying to determine whether a particular record has been changed. Thanks in advance Matthew mat@softhouse.co.uk
Informix has no generic built-in TIMESTAMP column attached to every row as
some databases do. You CAN however, alter the table to contain a column,
name it timestamp if you like, of type:
timestamp DATETIME YEAR TO FRACTION(3) DEFAULT CURRENT
and it will serve for inserts. To maintain for updates just add an update
trigger:
CREATE TRIGGER mytable_TS ON mytable FOR UPDATE .......
Art S. Kagel
Matthew Herbert wrote:
>
> Hi
>
> Does anyone know whether Informix supports the symbolic constant TIMESTAMP
> for individual records. I am trying to determine whether a particular
> record has been changed.
>
> Thanks in advance
>
> Matthew
> mat@softhouse.co.uk
The keyword CURRENT returns the current time. For example,
UPDATE table SET
cola = value,
colb = value,
colz = CURRENT
WHERE ...
will set colz of all rows that match the WHERE clause to the current
time.
Is this what you are looking for?
Rudy
On Wed, 1 Sep 1999 11:33:48 +0100, "Matthew Herbert"
<Mat@softhouse.co.uk> wrote:
>Hi
>
>Does anyone know whether Informix supports the symbolic constant TIMESTAMP
>for individual records. I am trying to determine whether a particular
>record has been changed.
>
>Thanks in advance
>
>
>Matthew
>mat@softhouse.co.uk
>
>