On Mon, 2006-09-11 at 16:53 +1200, Mike C wrote: > create table blah (start_date timestamp, number_of_days integer); > insert into blah values (current_timestamp, 25); > select start_date + number_of_days from blah; > > The error I get is: > > ERROR: operator does not exist: timestamp without time zone + integer > HINT: No operator matches the given name and argument type(s). You > may need to add explicit type casts. > > But according to > http://www.postgresql.org/docs/8.1/static/functions-datetime.html the > + operator should support integers and treat them as days ( date > '2001-09-28' + integer '7'). Obviously typing a constant into the > query is a lot different from using the value of a column, but I would > have thought it would work. That's because your data type was "timestamp", not "date". I don't believe the documentation claims the + operator works on a timestamp and an integer. But it does claim (correctly) that it works on a date and an integer. The following example does work: create table blah (start_date date, number_of_days integer); insert into blah values (current_date, 25); select start_date + number_of_days from blah; Hope that helps a little, at least to explain the apparent disconnect from the documentation.
