Database Systems Quiz SE(Blue)

Which SQL clause is used to filter records before aggregation?

• where

• having

• order

• group by

Which keyword is used to remove duplicate values in SQL?

• ALL

• 'UNIQUE

• DISTINCT

• PRIMARY

"Which of the following is not an aggregate function?"

• SUM()

• AVG()

• COUNT()

• SELECT()

"The ________ clause is used to sort the result-set."

"The ________ constraint is used to ensure a column cannot have NULL values."

"Explain the difference between WHERE and HAVING clauses in SQL."

"What is a foreign key and why is it important in relational databases?"

What does SQL stand for?

• Statement Query Language

• Structured Query Language

• Simple Quick Language

• Sequential Query Logic

Which function returns the average of a column?

• SUM()

• COUNT()

• AVG()

• MIN()

What does the NOT NULL constraint do?

• Allows NULL values

• Sets default values

• Duplicates values

• Restricts NULL values