-- Suggested testing environment: -- https://www.db-fiddle.com/ with MySQL version set to 8 -- Example case create statement: CREATE TABLE questions ( id INTEGER NOT NULL PRIMARY KEY, name VARCHAR(50) NOT NULL, parentId INTEGER, FOREIGN KEY (parentId) REFERENCES questions(id) ); INSERT INTO questions (id, name, parentId) VALUES (0, 'SQL select', NULL), (1, 'SQL select v2', 0), (2, 'C# tuples', NULL), (3, 'SQL select v3', 1); DELIMITER // CREATE PROCEDURE findAllVersions( IN questionId INTEGER ) BEGIN -- Write your code here END; // DELIMITER ; -- Example case: CALL findAllVersions(1) -- Expected output (in any order): -- id -- --- -- 0 -- 1 -- 3