PL/SQL基础(四)

PL\SQL中判断与循环
declare
tmpsal emp.sal%type;
begin
select sal into tmpsal from emp where empno=4321;
if(tmpsal<320) then
dbms_output.put_line('less');
elseif(tmpsal<400) then
dbms_output.put_line('mid');
else//最后没有then
dbms_output.put_line('great');
end if;
end;
do-while
declare
i binary_integer=1;
begin
loop
dbms_output.put_line(i);
i:=i+1;
exit while (i>=20);
end loop;
end;

while

declare
i binary_integer=1;
begin
while i<20 loop
dbms_output.put_line(i);
i:=i+1;
end loop;
end;

for
declare
k binary_integer;
begin
for k in 2..20 loop
dbms_output.put_line(k);
end loop;
for k in reverse 2..20 loop
dbms_output.put_line(k);
end loop;
end;