Table: Customers
+---------------+---------+ | Column Name | Type | +---------------+---------+ | customer_id | int | | customer_name | varchar | | email | varchar | +---------------+---------+ customer_id is the primary key for this table. Each row of this table contains the name and the email of a customer of an online shop.
Table: Contacts
+---------------+---------+ | Column Name | Type | +---------------+---------+ | user_id | id | | contact_name | varchar | | contact_email | varchar | +---------------+---------+ (user_id, contact_email) is the primary key for this table. Each row of this table contains the name and email of one contact of customer with user_id. This table contains information about people each customer trust. The contact may or may not exist in the Customers table.
Table: Invoices
+--------------+---------+ | Column Name | Type | +--------------+---------+ | invoice_id | int | | price | int | | user_id | int | +--------------+---------+ invoice_id is the primary key for this table. Each row of this table indicates that user_id has an invoice with invoice_id and a price.
Write an SQL query to find the following for each invoice_id:
customer_name: The name of the customer the invoice is related to.
price: The price of the invoice.contacts_cnt: The number of contacts related to the customer.trusted_contacts_cnt: The number of contacts related to the
customer and at the same time they are customers to the shop. (i.e His/Her email
exists in the Customers table.)
Order the result table by invoice_id.
The query result format is in the following example:
Customers table:
+-------------+---------------+--------------------+
| customer_id | customer_name | email |
+-------------+---------------+--------------------+
| 1 | Alice | alice@leetcode.com |
| 2 | Bob | bob@leetcode.com |
| 13 | John | john@leetcode.com |
| 6 | Alex | alex@leetcode.com |
+-------------+---------------+--------------------+
Contacts table:
+-------------+--------------+--------------------+
| user_id | contact_name | contact_email |
+-------------+--------------+--------------------+
| 1 | Bob | bob@leetcode.com |
| 1 | John | john@leetcode.com |
| 1 | Jal | jal@leetcode.com |
| 2 | Omar | omar@leetcode.com |
| 2 | Meir | meir@leetcode.com |
| 6 | Alice | alice@leetcode.com |
+-------------+--------------+--------------------+
Invoices table:
+------------+-------+---------+
| invoice_id | price | user_id |
+------------+-------+---------+
| 77 | 100 | 1 |
| 88 | 200 | 1 |
| 99 | 300 | 2 |
| 66 | 400 | 2 |
| 55 | 500 | 13 |
| 44 | 60 | 6 |
+------------+-------+---------+
Result table:
+------------+---------------+-------+--------------+----------------------+
| invoice_id | customer_name | price | contacts_cnt | trusted_contacts_cnt |
+------------+---------------+-------+--------------+----------------------+
| 44 | Alex | 60 | 1 | 1 |
| 55 | John | 500 | 0 | 0 |
| 66 | Bob | 400 | 2 | 0 |
| 77 | Alice | 100 | 3 | 2 |
| 88 | Alice | 200 | 3 | 2 |
| 99 | Bob | 300 | 2 | 0 |
+------------+---------------+-------+--------------+----------------------+
Alice has three contacts, two of them are trusted contacts (Bob and John).
Bob has two contacts, none of them is a trusted contact.
Alex has one contact and it is a trusted contact (Alice).
John doesn't have any contacts.