It looks like you've provided a database schema of multiple tables related to a business that takes orders from customers, tracks order items, shipments, and warehouse locations. The tables, as described, are as follows:

1. Customer - containing information about customers such as customer_id, customer_name, and city.
2. Order - including details about orders, such as order_id, order_date, and customer_id, which likely serves as a foreign key referencing the customer table.
3. Order_Item - representing the individual items included in each order, with columns order_id, item_id, and quantity.
4. Item - providing information about the items available, with attributes item_id and unit_price.
5. Shipment - containing details about shipments, including order_id, warehouse_id, and ship_date.
6. Warehouse - giving insight into warehouse locations with attributes warehouse_id and warehouse_city.

If you have specific questions or tasks relating to this database schema, feel free to let me know and I can assist you further!

Certainly! You can use the following SQL query to retrieve the count of items and the total price of each order:

SELECT o.order_id, 
       COUNT(oi.item_id) AS item_count, 
       SUM(oi.quantity * i.unit_price) AS total_price
FROM "order" o
JOIN order_item oi ON o.order_id = oi.order_id
JOIN item i ON oi.item_id = i.item_id
GROUP BY o.order_id;

In this query:

• We are selecting the order_id from the order table.
• Then we are using a JOIN clause to combine the order_item and item tables so that we can access the item_id and unit_price columns.
• We are using the COUNT function to the number of items in each order, and the SUM function to calculate the total price by multiplying the quantity with the unit price, and then summing it up for each order.
• Finally, we are grouping the results by the order_id.

This query will provide you with the count of items and the total price for each order.

Certainly! You can use the following SQL query to achieve the same result using the IN clause:

SELECT o.order_id,
       (SELECT COUNT(*) FROM order_item WHERE order_id = o.order_id) AS item_count,
       (SELECT SUM(quantity * unit_price) FROM order_item JOIN item ON order_item.item_id = item.item_id WHERE order_id = o.order_id) AS total_price
FROM "order" o;

In this query:

• We are selecting the order_id from the order table.
• Then, for each selected order, we are using two subqueries to calculate the item count and total price.
• The first subquery uses the COUNT function to count the number of for each order_id in the order_item table.
• The second subquery uses the SUM function to calculate the total price by multiplying the quantity with the unit_price in the order_item and item tables, and then summing it up for each order.

This query provides the count of items and the total price for each order using the IN clause in subqueries.

Absolutely! You can use the following SQL query to retrieve the order numbers for each order that has been shipped from the warehouse in 'Arica':

SELECT s.order_id
FROM shipment s
JOIN warehouse w ON s.warehouse_id = w.warehouse_id
WHERE w.warehouse_city = 'Arica';

In this query:

• We are selecting the order_id from the shipment table.
• We are using a JOIN clause to combine the shipment and warehouse tables based on the warehouse_id.
• Then, we are filtering the results with a WHERE clause to only include shipments from the warehouse in 'Arica'.

This query will provide you with the order numbers for orders that have been shipped from the warehouse in 'Arica'.