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Creating Basic SQL Reports in PostgreSQL

Introduction
Multiple metrics for a single object
Metrics for two groups
Ratios and percentages
Global vs. specific metrics
Summary
18. Question 4

Instruction

Fantastic! Here's your last question.

Exercise

What percentage of all orders placed in 2016 were generated by each customer? Show three columns:

  1. customer_id.
  2. order_count – the number of orders placed by that customer in 2016.
  3. order_count_percentage – the percentage of orders. placed by that customer in 2016, compared to all orders placed in 2016. Round the value to two decimal places.

Stuck? Here's a hint!