oracle创建复合触发器

create or replace trigger tr_stuinfor for update of name on tb_tri compound trigger 
a int;--在触发器中定义变量
before statement is    -- 触发语句执行前
begin
-- ...
end  before statement;

before each row is   -- 每条记录修改前
begin
null;
-- ...
end before each row;

after each row is    -- 每条记录修改后
begin
null;
-- ...
end after each row;

after statement is   -- 触发语句执行后
begin
null;
-- ...
end after statement;

end tr_stuinfor;