Обсуждение: Q:Update Rule

 I want  to save the user and date in a row when the user changed it.
If I use an update rule, how can I prevent a loop ?

Bad example:

create rule  r_changed
    as on update to requesttable
    do update requesttable
        set changed_by = current_user,
               date_of_last_change = current_date;


What is better ?


Detlef

Hello Detlef,

lunedì, 21 settembre 98, you wrote:

DBSNO2>  I want  to save the user and date in a row when the user changed it.
DBSNO2> If I use an update rule, how can I prevent a loop ?

DBSNO2> Bad example:

DBSNO2> create rule  r_changed
DBSNO2>     as on update to requesttable
DBSNO2>     do update requesttable
DBSNO2>         set changed_by = current_user,
DBSNO2>                date_of_last_change = current_date;


DBSNO2> What is better ?

There's an example in the directory
pgsql/contrib/spi/insert_username.* that insert the
username when the user update or insert a row into the table.
I modified this example to insert CURRENT_USER and CURRENT_TIMESTAMP
into the row.
It is very sample to implement but if you want I may send it to you.

                        Jose'