PHP, MySQL, and SQL Online Test

Consider the following table:

CREATE TABLE users (
  id BIGINT NOT NULL AUTO_INCREMENT PRIMARY KEY,
  username VARCHAR(50) NOT NULL
);

The following query is used to paginate the table:

SELECT * FROM users ORDER BY username LIMIT 5 OFFSET 15;

Select all the true statements about this method of pagination.

(multiple correct answers possible)

Given the following data definition, write a query that returns the number of students whose first name is John.

TABLE students
   id INTEGER PRIMARY KEY,
   firstName VARCHAR(30) NOT NULL,
   lastName VARCHAR(30) NOT NULL

Implement a groupByOwners function that:

• Accepts an associative array containing the file owner name for each file name.
• Returns an associative array containing an array of file names for each owner name, in any order.

For example, for associative array ["Input.txt" => "Randy", "Code.py" => "Stan", "Output.txt" => "Randy"] the groupByOwners function should return ["Randy" => ["Input.txt", "Output.txt"], "Stan" => ["Code.py"]].