Loops with PL/SQL

1. Basic loop

loop
  /* statements */
end loop;

2. While loop

while a > b loop
  /* statements */
end loop

　　

3. For loop

for i in 1..1000 loop
    insert into a values(i,i*2);
end loop;

for i in reverse 1..1000 loop
    insert into a values(i,i*2);
end loop;

　　

4. Cursor for loop

for rec in (select col_1, col_2 from table_a) loop
  /*Statements, use rec.col_1 and rec.col_2 */
end loop;

for rec in cursor_name loop
  /*Statements, use rec.col_1 and rec.col_2 */
end loop;

for rec in cursor_name(cursor_param_1, cursor_param_2...) loop
  /*Statements, use rec.col_1 and rec.col_2 */
end loop;

　　

5. Labels

　　Each of the loops can be labeled

<<label_name>>
loop
  ....
end loop label_name;

　　When a loop is labeled, the exit statement can then refer to that label:

begin
  <<i_loop>> for i in 1 .. 10 loop
    <<j_loop>> for j in 1 .. 10 loop
      dbms_output.put(to_char(j, '999'));
      exit j_loop when j=i;
    end loop;
    dbms_output.new_line;
  end loop;
end;

　　

6. exit

exit;
exit when foo > bar;

exit label_name;
exit label_name when foo > bar;