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..

SELECT query_name, ROUND(AVG(rating / position), 2) AS quality, ROUND(SUM(rating Table: Queries+-------------+---------+| Column Name | Type |+-------------+---------+| query_name | varchar || result | varchar || position | int || rating | int |+-------------+---------+This table may have duplicate rows.This table contains information collected from some queri..

Table: 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 ..

Table: Prices+---------------+---------+| Column Name | Type |+---------------+---------+| product_id | int || start_date | date || end_date | date || price | int |+---------------+---------+(product_id, start_date, end_date) is the primary key (combination of columns with unique values) for this table.Each row of this table indicates the price of the produc..

Table: Signups+----------------+----------+| Column Name | Type |+----------------+----------+| user_id | int || time_stamp | datetime |+----------------+----------+user_id is the column of unique values for this table.Each row contains information about the signup time for the user with ID user_id. Table: Confirmations+----------------+----------+| Column Name | Type ..