存储过程语法1：
create or replace procedure judge(a outnumber) as
cn number(4);
begin
select count(*) into cn from dual;
if cn = 0then
begin
dbms_output.put_line('aa');
end;
endif;
if cn = 1 then
begin
a := cn;
dbms_output.put_line('bb');
end;
end if;
exception
when others then
rollback;
end;
存储过程语法2:
create or replace procedure judge3(a outnumber) as
cn number(4);
begin
select count(*) into cn from dual;
if cn = 0 then
dbms_output.put_line('aa');
else
a := cn;
dbms_output.put_line('bb');
end if;
exception
when others then
rollback;
end;