LU04.A04 - SQL-DQL: Selects with Aggregate Functions

• Work type: individual
• Timeframe: 20 Minutes
• Means of aid:
  • only teaching materials, no websearch, no use of ai.
  • W3Schools | SQL Editor
• Expected result: Semantically and syntactically correct SQL statements according to the requirements of the case studies.

The following ERD describes a order database for a a shop.

The general assignment is to develop DQL commands that matches the requirements below:

We want to know which of our products is actually the most expensive.

SELECT max(price)
FROM Products;

What is the lowest price for the products of the supplier with id = 12?

SELECT max(price) 
FROM Products
WHERE SupplierID = 12;

What is the average price for products of supplier 3?

SELECT AVG(price) 
FROM Products
WHERE SupplierID = 3;

How many orders do we currently have in our data-base system from the customer with id = 5?

SELECT count(customerID)
FROM Orders
where customerID = 5;

Lösung

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