Query Optimization | MCQs

Explanation

A "Select query" is used to retrieve data from a database.

It can filter records to show employees earning more than $5000 a month by specifying conditions.

Explanation

• The correct answer is: Dept_id should not be used in group by clause (although this is not the case in the given query, as it uses dept_name)
• The error in the statement is that the ID column is not included in the GROUP BY clause. When using an aggregate function like AVG, all non-aggregated columns in the SELECT clause must be included in the GROUP BY clause.