What happens if you don't use GROUP BY in SQL?

Is it necessary to use GROUP BY in SQL?

The HAVING clause is used instead of WHERE with aggregate functions. While the GROUP BY Clause groups rows that have the same values into summary rows. The having clause is used with the where clause in order to find rows with certain conditions. The having clause is always used after the group By clause.

Can SQL have having Without GROUP BY?

You can also use the having clause with the Transact-SQL extension that allows you to omit the group by clause from a query that includes an aggregate in its select list. These scalar aggregate functions calculate values for the table as a single group, not for groups within the table.

What happens if I GROUP BY a column that is not in the select statement?

In MySQL, when you try to select a column that isn't used in the GROUP BY clause, or in an aggregate function inside the statement, it is not a valid statement according to SQL standard and will cause an error.

What happens when group functions are used without GROUP BY clause?

If you use a group function in a statement containing no GROUP BY clause, it is equivalent to grouping on all rows. If you want a GROUP BY clause on your query then append GROUP BY NULL to it.