情况1:没有查到数据
ex:
declare tid number;
begin
select id into tid from customer where id = '1254';
exception
when no_date_found then
tid := 0;
end;
ex:
declare tid number;
begin
select id into tid from customer where id = '1254';
exception
when no_date_found then
tid := 0;
end;
no_data_found exception2. 得到数据大于1条..too_many_rows exception