SQLServer SQL Group By vs Distinct
Difference between GROUP BY and DISTINCT
The query below uses GROUP BY to perform aggregated calculations.
SELECT
storeName,
COUNT(*) AS total_nr_orders,
COUNT(DISTINCT userId) AS nr_unique_customers,
AVG(orderValue) AS average_order_value,
MIN(orderDate) AS first_order,
MAX(orderDate) AS lastOrder
FROM
orders
GROUP BY
storeName;While DISTINCT is used to list a unique combination of distinct values for the specified columns.
SELECT DISTINCT
storeName,
userId
FROM
orders;