1. WHERE clause can be used with a Select, Update and Delete Statement Clause but
the HAVING clause can be used only with a Select statement.
2. We can’t use an aggregate functions in the WHERE clause unless it is in a sub-query
contained in a HAVING clause whereas we can use an aggregate function in the
HAVING clause. We can use a column name in the HAVING clause but the column
must be contained in the group by clause.
3. WHERE is used before the GROUP BY clause whereas a HAVING clause is used to
impose a condition on the GROUP Function and is used after the GROUP BY clause in
the query.
4. A WHERE clause applies to each and every row whereas a HAVING clause applies to
summarized rows (summarized with GROUP BY).
5. In the WHERE clause the data that is fetched from memory depending on a
condition whereas in HAVING the completed data is first fetched and then separated
depending on the condition.