Oracle cursor loop and time function instances

Time Function instance:

Select sysdate, add_months (sysdate, 12) from dual; -- add 1 year

Select sysdate, add_months (sysdate, 1) from dual; -- add January

Select sysdate, to_char (sysdate + 7, 'yyyy-mm-dd hh24: MI: ss') from dual; -- add 1 week

Select sysdate, to_char (sysdate + 1, 'yyyy-mm-dd hh24: MI: ss') from dual; -- add 1 day

Select sysdate, to_char (sysdate + 1/24, 'yyyy-mm-dd hh24: MI: ss') from dual; -- add 1 hour

Select sysdate, to_char (sysdate + 1/24/60, 'yyyy-mm-dd hh24: MI: ss') from dual; -- add 1 minute

Select sysdate, to_char (sysdate + 1/24/60/60, 'yyyy-mm-dd hh24: MI: ss') from dual; -- add 1 second

Cursor loop instance:

Multiple pieces of data are queried, but the data needs to be recycled one by one, similar to traversal in Java.
Foreign Language House

declare
v_yhzh varchar2 (20); -- defines the variable user number
v_phone varchar2 (11 ); -- mobile phone number
cursor cur_1 is select dy. user_sid, dy. user_mobile from dx. dy_order dy; -- save the result to cur_1
begin
open cur_1; -- open the cursor
loop -- loop
fetch cur_1 into v_yhzh, v_phone; -- The cursor values are sequentially assigned to v_yhzh
exit when cur_1 % notfound; -- loop condition
dbms_output.put_line (v_yhzh | '---' | v_phone); -- print the output
end loop; -- cyclic completion
inland transportation
close cur_1; -- close the cursor
end; -- end