o Suppose we have a ClubMember table created by CREATE TABLE ClubMember ( id INT PRIMARY KEY, name VARCHAR(40) NOT NULL, registerTime DATETIME NOT NULL ); INSERT INTO ClubMember VALUES (1, 'David', (2, 'Jessica', (3, 'Andy', (4, 'Jenny', (5, 'Bill', 2020-5-28 16:25'), 2020-5-28 17:10'), 2020-1-1 11:11'), '2019-12-30'), 2020-5-27 10:45'); and we would like to ask the following query questions: Who registered with the club within 2 hours as David did? Who registered on the same date as David? Then these two functions DATEADD and CONVERT can come to our assistance as the solutions may be formulated respectively by SELECT id, name, registerTime FROM ClubMember WHERE name 'David' AND - exclude 'David' himself DATEADD(HOUR, -2, registerTime)