The topic of odd and even measurements is discussed in the context of a Google SQL interview question. The key takeaways from this discussion include the utilization of window functions such as ROW_NUMBER(), the concise use of aggregate functions with the CASE clause, and the conversion of datetime type by employing DATE_TRUNC and CAST methods.
WITH cte AS ( SELECT DATE_TRUNC('day', measurement_time) AS measurement_day, measurement_value, row_number() OVER ( PARTITION BY CAST(measurement_time AS DATE) ORDER BY measurement_time ) AS measurement_num FROM measurements ) SELECT measurement_day, SUM( CASE WHEN measurement_num % 2 = 1 THEN measurement_value ELSE 0 END ) as odd_sum, SUM( CASE WHEN measurement_num % 2 = 0 THEN measurement_value ELSE 0 END ) as even_sum FROM cte GROUP BY measurement_day ORDER BY 1
- Data Lemur. (n.d.). Odd and Even Measurements. Retrieved from https://datalemur.com/questions/odd-even-measurements