MySQL insert trigger only for new rows -

i want trigger in mysql inserts information of table in table b if it´s new entry.

my trigger inserts entrys of table table b if new entry in table made:

create trigger trigger_insert after insert on tablea each row  begin     insert `tableb`         (         `id`,         `active`,         `created_at`,         `updated_at`         )     select         `id`,         `active`,         `created_at`,         now()             tablea;  end; 

my problem is, have second trigger inserts entrys of tablea after update. can´t make id unique. result should tableb kind of history insert , update statements in tablea

would thankfull help!

your problem select rows tablea. assume intend:

insert `tableb`(`id`, `active`, `created_at`, `updated_at`)     select new.id, new.active, new.created_at, mnw() 

the more general answer question add unique constraint on tableb. assuming id defines duplicate entry:

alter table tableb add constaint unq_tableb_id unique (id); 

then change insert ignore duplicate inserts:

insert `tableb`(`id`, `active`, `created_at`, `updated_at`)     select `id`, `active`, `created_at`, mnw()     tablea     on duplicate key update id = values(id); 

if duplicates still needed when use new, can combine these:

insert `tableb`(`id`, `active`, `created_at`, `updated_at`)     select new.id, new.active, new.created_at, mnw()     on duplicate key update id = values(id); 

both these queries assume id used define duplicate.