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Introduction
Quick refresher
PARTITION BY ORDER BY with ranking
PARTITION BY ORDER BY with window frames
PARTITION BY ORDER BY with analytical functions
18. Practice 1
Summary

## Instruction

Okay, let's practice the usage of PARTITION BY ORDER BY with analytical functions a bit more.

## Exercise

For each row of the sales figures, show the following information: store_id, day, revenue, revenue a week before and the ratio of revenue today to the revenue a week before expressed in percentage with 2 decimal places.

### Stuck? Here's a hint!

Use, among others, LAG(revenue,7) OVER(PARTITION BY store_id ORDER BY day).