Trigger

[Daft69]

Hi,

I must do a auto number increse but I don't know how to do that !

I explain : I have a field : ID who is a number and when I make an insertion, I don't put any ID in the request but oracle take the max and add 1 !

I hope it's clear, I know that my english is not very good but I need help !!

Bye

 

[Kenrae]

If I've understood you correctly, you need to use a sequence there.

 

[Daft69]

sequence ??

I don't know anything in trigger ! Can you explain more please ?

 

[carp]

A sequence is a database object that generates numbers. Every time you do an insert, your code (be it a procedure or trigger) goes to the sequence for the next number:

CREATE SEQUENCE my_seq;

INSERT INTO my_table VALUES(my_seq.NEXTVAL, data_for_column_1,......);

Be advised that there may be breaks in your sequences; that is, there can be gaps in your numbers due to things like rollbacks, system failures, etc. If this is a problem (that is, if you have to account for every number), then your trigger/procedure will need to find the current high number and then increment it:

SELECT max(id_number) INTO max_num FROM my_table;
INSERT INTO my_table VALUES (max_num+1, data_for_column_1...);

This is relatively expensive in terms of resources and time.

 

[Daft69]

Thank you !!