Description

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Your professor gave the class a bonus task: Write a program that will check the answers for the latest test. The program will be given a table answers with the following columns:

• id: the unique ID of the question;
• correct_answer: the correct answer to the question, given as a string;
• given_answer: the answer given to the question, which can be NULL.

Your task is to return the table with a column id and a column checks, where for each answers id the following string should be returned:

• "no answer" if the given_answer is empty;
• "correct" if the given_answer is the same as the correct_answer;
• "incorrect" if the given_answer is not empty and is incorrect.

Order the records in the answer table by id.

Example

For given table answers

id	correct_answer	given_answer
1	a	a
2	b	NULL
3	c	b

the output should be

id	checks
1	correct
2	no answer
3	incorrect

• [execution time limit] 10 seconds (mysql)

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CREATE PROCEDURE testCheck()
    SELECT id, IF ( given_answer IS NULL, 'no answer', IF ( given_answer =correct_answer, 'correct', 'incorrect') ) AS checks
    FROM answers
    ORDER BY id;