declare mydate date;
begin
select begintime into mydate from mytable where rownum<=1;
exception when no_data_found then
.... --显示没有数据,或给mydate赋缺省值
end;
begin
select begintime into mydate from mytable where rownum<=1;
exception when no_data_found then
.... --显示没有数据,或给mydate赋缺省值
end;
mydate date;
begin
select begintime into mydate from mytable where rownum<=1;
exception
when not_data_found then --也可以 when others then
.... --显示没有数据,或给mydate赋缺省值
end;
select begintime
from mytable
where rownum<=1;begin open c_date;
fetch c_date into mydate;
close c_date;end;