Odpowiedź:
Distinct :
SELECT distinct c.CompanyName, p.ProductName
FROM Customers C JOIN orders O on c.CustomerID = o.CustomerID
JOIN [Order Details] od on od.OrderID = o.OrderID
JOIN products p on p.ProductID = od.ProductID
WHERE c.Country = 'USA'
Order by i desc :
SELECT
ProductName,
Discontinued,
CASE Discontinued
WHEN 0 THEN 'Nie'
WHEN 1 THEN 'Tak'
ELSE 'Brak info'
END AS 'Czy wycofany?'
FROM
Products
order by 3 desc
Limit :
SELECT column_name(s)
FROM table_name
WHERE condition
LIMIT number;
Wyjaśnienie:
