How do you list all users in this table?+-------+-------------------------------------------------------------------------------------------------------------------------------+| Table | Create Table |+-------+-------------------------------------------------------------------------------------------------------------------------------+| users | CREATE TABLE `users` ( `id` int(11) DEFAULT NULL, `name` varchar(256) DEFAULT NULL, `age` int(11) DEFAULT NULL) ENGINE=InnoDB DEFAULT CHARSET=latin1 |+-------+-------------------------------------------------------------------------------------------------------------------------------+DELETE * FROM users;SELECT * FROM users;SELECT ALL users;

How do you list all users records with age > 21 in this table?+-------+-------------------------------------------------------------------------------------------------------------------------------+| Table | Create Table |+-------+-------------------------------------------------------------------------------------------------------------------------------+| users | CREATE TABLE `users` ( `id` int(11) DEFAULT NULL, `name` varchar(256) DEFAULT NULL, `age` int(11) DEFAULT NULL) ENGINE=InnoDB DEFAULT CHARSET=latin1 |+-------+-------------------------------------------------------------------------------------------------------------------------------+SELECT * FROM users WHERE age < 21;SELECT * FROM users WHERE age IS UP TO 21;SELECT * FROM users WHERE age > 21;SELECT * FROM users WHERE age BETWEEN 21 AND 89;

Users+-------------+---------+| Column Name | Type |+-------------+---------+| user_id | int || user_name | varchar |+-------------+---------+user_id is the primary key (column with unique values) for this table.Each row of this table contains the name and the id of a user. Table: Register+-------------+---------+| Column Name | Type |+-------------+---------+| contest_id | int || user_id | int |+-------------+---------+(contest_id, user_id) is the primary key (combination of columns with unique values) for this table.Each row of this table contains the id of a user and the contest they registered into. Write a solution to find the percentage of the users registered in each contest rounded to two decimals.Return the result table ordered by percentage in descending order. In case of a tie, order it by contest_id in ascending order.The result format is in the following example. Example 1:Input: Users table:+---------+-----------+| user_id | user_name |+---------+-----------+| 6 | Alice || 2 | Bob || 7 | Alex |+---------+-----------+Register table:+------------+---------+| contest_id | user_id |+------------+---------+| 215 | 6 || 209 | 2 || 208 | 2 || 210 | 6 || 208 | 6 || 209 | 7 || 209 | 6 || 215 | 7 || 208 | 7 || 210 | 2 || 207 | 2 || 210 | 7 |+------------+---------+Output: +------------+------------+| contest_id | percentage |+------------+------------+| 208 | 100.0 || 209 | 100.0 || 210 | 100.0 || 215 | 66.67 || 207 | 33.33 |+------------+------------+Explanation: All the users registered in contests 208, 209, and 210. The percentage is 100% and we sort them in the answer table by contest_id in ascending order.Alice and Alex registered in contest 215 and the percentage is ((2/3) * 100) = 66.67%Bob registered in contest 207 and the percentage is ((1/3) * 100) = 33.33%

1What command can we use to show a list of users on the system?

How to you add a new record in the table users?+-------+-------------------------------------------------------------------------------------------------------------------------------+| Table | Create Table |+-------+-------------------------------------------------------------------------------------------------------------------------------+| users | CREATE TABLE `users` ( `id` int(11) DEFAULT NULL, `name` varchar(256) DEFAULT NULL, `age` int(11) DEFAULT NULL) ENGINE=InnoDB DEFAULT CHARSET=latin1 |+-------+-------------------------------------------------------------------------------------------------------------------------------+INSERT users (id, name, age) VALUES (2, “Betty”, 30);INSERT INTO users (id, name) VALUES (2, “Betty”, 30);INSERT INTO users (id, name, age) VALUES (2, “Betty”, 30);INSERT INTO users (id, name, age) VALUES (2, “Betty”);

How do you delete the users record with id = 89 in this table?+-------+-------------------------------------------------------------------------------------------------------------------------------+| Table | Create Table |+-------+-------------------------------------------------------------------------------------------------------------------------------+| users | CREATE TABLE `users` ( `id` int(11) DEFAULT NULL, `name` varchar(256) DEFAULT NULL, `age` int(11) DEFAULT NULL) ENGINE=InnoDB DEFAULT CHARSET=latin1 |+-------+-------------------------------------------------------------------------------------------------------------------------------+DELETE users WHERE id = 89;DELETE FROM users WHERE id = 89;DELETE FROM users;DELETE FROM users WHERE id IS EQUAL TO 89;