using group by to solve duplicates
I don't understand how does group by solve the problem of duplicates, can I have more explanation ?
Thanks for reaching out.
The reason for removing duplicates using the GROUP BY clause is because this clause groups the result set by some column and thus we do not have any duplicates.
The GROUP BY statement groups rows that have the same values into summary rows, like "find the number of customers in each country". The GROUP BY statement is often used with aggregate functions (COUNT(), MAX(), MIN(), SUM(), AVG()) to group the result-set by one or more columns.
Hope this helps.