Date and time calculation?

[adrianjhull]

I have a table with 4 fields.

Field 1: as_date datatype: date
Field 2: as_time datatype: number precision:4 scale:2

Field 3: dc_date datatype: date
Field 4: dc_time datatype: number precision:4 scale:2

I need to subtract the comnined value of field 3/4 from the combined value of 1/2 in order to find out how many days and hours have elapsed.

I am not sure how to do merge the fields and perform a calculation with the datatypes being different.

Possible? 

My thanks in advance.

Adrian

[bensr]

Maybe this example will help:
set serveroutput on
clear
declare
ld_date1 date := to_date('20021204','yyyymmdd');
ld_date2 date := to_date('20021207','yyyymmdd');
ln_time1 number(4,2) := 14.24; -- Hours assumed
ln_time2 number(4,2) := 12.30; -- Hours assumed

ln_diff number (10,2);
begin
ln_diff := ld_date2 - ld_date1; -- Difference in days
dbms_output.put_line('Diff days : '||ln_diff);
ln_diff := ln_diff * 24 ; -- Difference in hours
dbms_output.put_line('Diff hours : '||ln_diff);
ln_diff := ln_diff + (ln_time2 - ln_time1);
dbms_output.put_line('Diff total : '||ln_diff);
end;
/