Table: Products+---------------+---------+| Column Name | Type |+---------------+---------+| product_id | int || new_price | int || change_date | date |+---------------+---------+(product_id, change_date) is the primary key (combination of columns with unique values) of this table.Each row of this table indicates that the price of some product was changed to a new price ..

Table: Employees+-------------+----------+| Column Name | Type |+-------------+----------+| employee_id | int || name | varchar || reports_to | int || age | int |+-------------+----------+employee_id is the column with unique values for this table.This table contains information about the employees and the id of the manager they report to. Some employees do no..

Table: MyNumbers+-------------+------+| Column Name | Type |+-------------+------+| num | int |+-------------+------+This table may contain duplicates (In other words, there is no primary key for this table in SQL).Each row of this table contains an integer. A single number is a number that appeared only once in the MyNumbers table.Find the largest single number. If there is no single n..

Table: Activity+--------------+---------+| Column Name | Type |+--------------+---------+| player_id | int || device_id | int || event_date | date || games_played | int |+--------------+---------+(player_id, event_date) is the primary key (combination of columns with unique values) of this table.This table shows the activity of players of some games.Each row is a recor..

Table: Delivery+-----------------------------+---------+| Column Name | Type |+-----------------------------+---------+| delivery_id | int || customer_id | int || order_date | date || customer_pref_delivery_date | date |+-----------------------------+---------+delivery_id is the column of unique values of this tabl..

Table: Transactions+---------------+---------+| Column Name | Type |+---------------+---------+| id | int || country | varchar || state | enum || amount | int || trans_date | date |+---------------+---------+id is the primary key of this table.The table has information about incoming transactions.The state column is an enum of type ["approved..