SQL: difference between PARTITION BY and GROUP BY
They’re used in different places. GROUP BY modifies the entire query, like: select customerId, count(*) as orderCount from Orders group by customerId But PARTITION BY just works on a window function, like ROW_NUMBER(): select row_number() over (partition by customerId order by orderId) as OrderNumberForThisCustomer from Orders GROUP BY normally reduces the number of rows returned … Read more