Compare SQL DATE to NUMBER

Question

I am working with the following SQL statement and can't seem to get the syntax correct:

idSelectQuery=Select "numberprgn" 
              from "SMT1"."CM3R1M1" 
              where "category" != 'KM Document' 
          AND ("sysmodtime" - TO_DATE('1970-01-01', 'YYYY-MM-DD')) * 86400000 > ?

Where the '?' is the current system time as a number - which is actually epoch time.

This statement fails because of:

ORA-00932: inconsistent datatypes: expected NUMBER got DATE

I need to be able to compare the sysmodtime to the? time value, although I can't figure out a way to properly do this... I'm not sure if i can cast sysmodtime to char then to number, because I know its not possible to cast date to number directly.

Anyone have any suggestions to get this to work?

Thanks

Answer 1

I suspect you want

"sysmodtime" > TO_DATE('1970-01-01', 'YYYY-MM-DD') + (?/ 86400000)

Assuming that? represents the number of milliseconds since Jan 1, 1970. Writing the query this way makes it possible to use an index on "sysmodtime".

Now, realistically, you probably want to create a function that takes a numeric time and converts it to a date, ie

CREATE FUNCTION epoch_to_date( p_epoch IN NUMBER )
  RETURN DATE
IS
BEGIN
  RETURN TO_DATE('1970-01-01', 'YYYY-MM-DD') + (p_epoch/ 86400000);
END;

that you can call in your query

"sysmodtime" > epoch_to_date( ? )