Mastering Basic SQL Queries

What is the purpose of the `SELECT` statement in SQL?

• To delete data from a database

• To retrieve data from a database

• To update data in a database

• To insert data into a database

Which clause is used to specify the table from which to retrieve data in an SQL query?

• SELECT

• WHERE

• FROM

• ORDER BY

What does the `WHERE` clause do in an SQL query?

• It sorts the data in ascending order

• It filters records based on specified conditions

• It groups data based on a column

• It limits the number of records returned

Which of the following SQL statements correctly selects all columns from a table named `students`?

• SELECT * FROM students;

• SELECT students FROM *;

• SELECT ALL FROM students;

• SELECT columns FROM students;

How would you write an SQL query to select only the `name` and `age` columns from a table called `people`?

• SELECT name, age FROM people;

• SELECT name AND age FROM people;

• SELECT name, age IN people;

• SELECT name, age OF people;

Which SQL query would you use to find all records in the `books` table where the `author` is 'J.K. Rowling'?

• SELECT * FROM books WHERE author = 'J.K. Rowling';

• SELECT * FROM books WHERE author IS 'J.K. Rowling';

• SELECT * FROM books WHERE author LIKE 'J.K. Rowling';

• SELECT * FROM books WHERE author IN 'J.K. Rowling';

What is the result of the following SQL query: `SELECT name FROM employees WHERE salary > 30000;`?

• It selects all employees with a salary less than £30,000

• It selects the names of employees with a salary greater than £30,000

• It selects all columns of employees with a salary greater than £30,000

• It selects the names of employees with a salary equal to £30,000

Which SQL statement would you use to select all records from the `orders` table where the `quantity` is less than 10?

• SELECT * FROM orders WHERE quantity < 10;

• SELECT * FROM orders WHERE quantity = 10;

• SELECT * FROM orders WHERE quantity > 10;

• SELECT * FROM orders WHERE quantity <= 10;