Perfect! Of course, there's also a function that shows a previous value, and its name is LAG(x):
SELECT name, opened, LAG(name) OVER(ORDER BY opened) FROM website;
Now, instead of showing the next opening date, we show the previous opening date. Take a look:
Note that you can always sort the rows in the reverse order with DESC and use LEAD(...) instead of LAG(...), or the other way around. In other words:
LEAD (...) OVER(ORDER BY ...)
is the same as
LAG (...) OVER (ORDER BY ... DESC)
and
LEAD (...) OVER(ORDER BY ... DESC)
is the same as
LAG (...) OVER (ORDER BY ...)
Show the statistics for the website with id = 3: day, number of clicks that day and the number of clicks on the previous day.
Note that there won't be any previous value for the first row.
Use LAG(clicks) and the right ORDER BY clause.
