• 创建表

drop table if exists ts;
create table ts (
    id      bigserial  primary key,
    tradeid integer ,
    email varchar(50),
    num integer,
    modified timestamp default current_timestamp
);

• 创建触发器函数

create or replace function upd_timestamp() returns trigger as
$$
begin
    new.modified = current_timestamp;
    return new;
end
$$
language plpgsql;

• 创建触发器

create trigger t_name before update on ts for each row execute procedure upd_timestamp();

• 测试代码：

insert into ts (tradeid,email,num) values (1223,'mike_zhang@live.com',1);
update ts set email='Mike_Zhang@live' where tradeid = 1223 ;

create unique index ts_tradeid_idx on ts(tradeid);
insert into ts(tradeid,email,num) values (1223,'Mike_Zhang@live.com',2) on conflict(tradeid) do update
set email = excluded.email,num=excluded.num;

select * from ts;