Help in interval function

Question

Dear Engineers
i run this code and it's work .when i replace (interval '30' minute) to (interval C minute) error show i need the interval accept from variable .if there are another function i can add minute or second to a time plz let me know .
declare
m timestamp;
n timestamp;
b timestamp;
c varchar2(10);
begin
m:=to_date('8:30:00','hh24:mi:ss');
n:=to_date('30:00','mi:ss'); -- 30 second will add to m
c:= extract ( minute from n);
b:=m+ interval '30' minute; -- here is the problem i want to replace '30' to variable c but error show when i replace it
dbms_output.put_line(b);
end;
Beast Regards
Michael

Answer 1

Hi, Michael,
Yes, there's a function: NUMTODSINTERVAL
b := m + NUMTODSINTERVAL (c, 'minute'); The first argument to NUMTODSINTERVAL is supposed to be a NUMBER, but if you use a VARCHAR2, it will be implicitly converted to a NUMBER. It's up to you to ensure that the string can be converted.
By the way,
n:=to_date('30:00','mi:ss'); -- 30 second will add to m sets n to 12:30 am (that's 30 minutes, not seconds) on the 1st day of the current month, e.g. 01-Jun-2010 00:30:00.000000.
n is a TIMESTAMP, so it will have a year, month and day.