loop循环：
create or replace procedure pro_test_loop is
i number;
begin
i:=0;
loop
? i:=i+1;
? dbms_output.put_line(i);
? if i>5 then
? ? exit;
? end if;
end loop;
end pro_test_loop;

while循环：
create or replace procedure pro_test_while is
i number;
begin
i:=0;
while i<5 loop
? i:=i+1;
? dbms_output.put_line(i);
end loop;
end pro_test_while;

for循环1：
create or replace procedure pro_test_for is
i number;
begin
i:=0;
for i in 1..5 loop
? dbms_output.put_line(i);
end loop;
end pro_test_for;

for循环2：
create or replace procedure pro_test_cursor is
userRow t_user%rowtype;
cursor userRows is
select * from t_user;
begin
for userRow in userRows loop
? ? dbms_output.put_line(userRow.Id||','||userRow.Name||','||userRows%rowcount);
end loop;
end pro_test_cursor;