create or replace trigger tr1
before insert /* либо: before, after; либо: insert, update delete */
on tbl1
begin
insert into audit(data) values (sysdate);
end;




create or replace trigger tr1 before insert on tbl1
begin
insert into tblaudit(id) values (4);
end;
insert into tbl1(id, name) values(1, 'first');



create or replace trigger tr2 before update on tbl1
for each row
begin
insert into tblaudit(id) values (5);
end;




select *
from user_triggers
where trigger_name='TR2';




alter trigger tr2 enable; // disable


create or replace trigger tr3
before insert on tbl1
for each row
declare
  p_txt varchar2(20);
begin
  p_txt := :new.name;
  insert into tblaudit(content) values(p_txt);
end;

create or replace trigger tr3
before insert on tbl1
for each row
declare
  p_txt tbl1.name%type;
begin
  p_txt := :new.name;
  insert into tblaudit(content) values(p_txt);
end;
create or replace trigger tr3
before insert on tbl1
for each row
declare
  p_txt tbl1.name%type;
  p_tbl1 tbl1%rowtype;
begin
  p_txt := :new.name;
  insert into tblaudit(content) values(p_tbl1.name);
end;

|| конкатенация


nvl(variable, value if NULL)



create or replace trigger tr4 before update or insert of name on tbl1
for each row
when (new.name = 'Vasya')
begin
insert into tblaudit(id) values (55);
end;