Re: trigger to access only the last transaction

That's what the FOR EACH ROW part of the statement is for. Your trigger
function will be executed once per each row that is modified / inserted:
http://www.postgresql.org/docs/9.4/static/sql-createtrigger.html.

Frank

On Mon, Mar 9, 2015 at 1:50 AM, avpro avpro <avprowebeden(at)gmail(dot)com> wrote:

> Sorry I forgot to mention: last insert could have multiple rows inserted
> and I would like to access all of them, not necessarily only the last one.
> That's my problem. Or I misunderstand the "last entry".
> Thank you.
> On 9 Mar 2015 08:29, "Marcos Almeida Azevedo" <marcos(dot)al(dot)azevedo(at)gmail(dot)com>
> wrote:
>
>>
>>
>> On Mon, Mar 9, 2015 at 6:01 AM, avpro avpro <avprowebeden(at)gmail(dot)com>
>> wrote:
>>
>>> hi all,
>>>
>>> i have two tables with several columns:
>>> table1
>>> idtaskhistory
>>> performedat
>>> ...
>>> idtask
>>>
>>> and
>>>
>>> table2
>>> idtask,
>>> manualdueat
>>> .....
>>>
>>>
>>> i created a trigger that does the following:
>>>
>>> CREATE TRIGGER del1
>>> AFTER INSERT
>>> ON table1
>>> FOR EACH ROW
>>> EXECUTE PROCEDURE taskdel;
>>>
>>> taskdel:
>>> CREATE OR REPLACE FUNCTION taskdel()
>>> RETURNS trigger AS
>>> $BODY$begin
>>> update table2
>>> SET
>>> manualdueat = null,
>>> FROM table1,
>>> where table1.idtask = table2.idtask;
>>> return new;
>>> END$BODY$
>>> LANGUAGE plpgsql VOLATILE
>>> COST 100;
>>> ALTER FUNCTION taskdel()
>>> OWNER TO user1;
>>>
>>> my idea was to have the info from column "manualdueat" deleted after the
>>> table1 has been updated. the problem i face is that all columns from table2
>>> will be deleted, not only my last entry where the insert has been done (I
>>> was thinking that table1.idtask = table2.idtask will work, but isn't); my
>>> question to you would be how to access only the last insert id in table1
>>> and make this trigger working. or do you have another walk arround?
>>>
>>
>> How about querying and order by primary key descending and get the first
>> one?
>>
>>
>>
>>> I'm using psql 9.4 on a windows system
>>>
>>> thank you for your ideas,
>>> John
>>>
>>
>>
>>
>> --
>> Marcos | I love PHP, Linux, and Java
>> <http://javadevnotes.com/java-float-to-string-examples>
>>
>