Interval data types
INTERVAL data types provide you with a very useful tool for performing arithmetic on date and time data types. For example, let's say our rental policy requires a DVD to be returned within 3 days. We can calculate the expected_return_date for a given DVD rental by adding an INTERVAL of 3 days to the rental_date from the rental table. We can then compare this result to the actual return_date to determine if the DVD was returned late.
Let's try this example in the exercise.
This exercise is part of the course
Functions for Manipulating Data in PostgreSQL
Exercise instructions
- Select the rental date and return date from the
rentaltable. - Add an
INTERVALof 3 days to therental_dateto calculate the expected return date`.
Hands-on interactive exercise
Have a go at this exercise by completing this sample code.
SELECT
-- Select the rental and return dates
___,
___,
-- Calculate the expected_return_date
rental_date + ___ ___ AS expected_return_date
FROM rental;