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.

(Select all acceptable answers.)

Given the following data definition, write a query that returns the number of students whose first name is John. String comparisons should be case sensitive.

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"]].