Testing out window functions
Window functions reference other rows within the report. There are a variety of window-specific functions to use, but all basic aggregation functions can be used as a window function. These include:
SUM()AVG()MAX()MIN()
The syntax of a window function is FUNCTION(value) OVER (PARTITION BY field ORDER BY field). Note that the PARTITION BY and ORDER BY clauses are optional. The FUNCTION should be replaced with the function of your choice.
In this exercise, you will run a few different window functions on the country_stats table.
Cet exercice fait partie du cours
Reporting in SQL
Exercice interactif pratique
Essayez cet exercice en complétant cet exemple de code.
SELECT
country_id,
year,
gdp,
-- Show the average gdp across all years per country
____ AS country_avg_gdp
FROM country_stats;