Lecture 10 - COMP1551

What is the primary purpose of SQL?

• To develop graphical applications

• To create machine learning models

• To manipulate data in relational databases

• To write low-level system programs

Which SQL category includes the `CREATE TABLE` statement?

• Data Definition Language (DDL)

• Data Manipulation Language (DML)

• Data Query Language (DQL)

• Data Control Language (DCL)

Which of the following SQL statements retrieves data from a table?

• INSERT

• UPDATE

• SELECT

• DELETE

What is the purpose of the `JOIN` operation in SQL?

• To delete data from two tables simultaneously

• To insert values into multiple tables

• To combine rows from two or more tables based on a related column

• To modify the schema of a table

Which SQL join returns only the matching rows from both tables?

• LEFT JOIN

• RIGHT JOIN

• FULL JOIN

• INNER JOIN

Which SQL function returns the total number of rows that match a condition?

• SUM()

• COUNT()

• AVG()

• MIN()

Which SQL clause is used to group rows based on a specific column?

• ORDER BY

• HAVING

• GROUP BY

• DISTINCT

What does the `AVG()` function do in SQL?

• Counts the number of rows in a table

• Finds the highest value in a column

• Calculates the average value of a column

• Groups rows based on a condition

Which SQL keyword is used to remove specific records from a table?

• DROP

• REMOVE

• DELETE

• ERASE

Which of the following is a logical operator in SQL?

• AND

• ADD

• SUM

• AVG