Упражнение 27

Консоль

Выполнить

SELECT Product.maker 
FROM Product INNER JOIN 
     Printer ON Product.model = Printer.model 
GROUP BY Product.maker;

SELECT Product.maker FROM Product INNER JOIN      Printer ON Product.model = Printer.model GROUP BY Product.maker;

    Схема

Консоль

Выполнить

SELECT PC.hd, Product.maker 
FROM PC INNER JOIN 
     Product ON PC.model = Product.model;

SELECT PC.hd, Product.maker FROM PC INNER JOIN      Product ON PC.model = Product.model;

    Схема

Консоль

Выполнить

SELECT PC.hd, Product.maker 
FROM PC INNER JOIN 
     Product ON PC.model = Product.model
WHERE Product.maker IN (SELECT Product1.maker 
                        FROM Product Product1  INNER JOIN 
                             Printer ON Product1.model = Printer.model 
                        GROUP BY Product1.maker
                        );

SELECT PC.hd, Product.maker FROM PC INNER JOIN      Product ON PC.model = Product.model WHERE Product.maker IN (SELECT Product1.maker                         FROM Product Product1  INNER JOIN                              Printer ON Product1.model = Printer.model                         GROUP BY Product1.maker                         );

    Схема

Консоль

Выполнить

SELECT Result.maker, AVG(result.hd) 
FROM (SELECT PC.hd, Product.maker 
      FROM PC INNER JOIN 
           Product ON PC.model = Product.model
      WHERE Product.maker IN (SELECT Product1.maker 
                              FROM Product Product1  INNER JOIN 
                                   Printer ON Product1.model = Printer.model 
                              GROUP BY Product1.maker
                              )
      ) AS result
GROUP BY result.maker;

SELECT Result.maker, AVG(result.hd) FROM (SELECT PC.hd, Product.maker       FROM PC INNER JOIN            Product ON PC.model = Product.model       WHERE Product.maker IN (SELECT Product1.maker                               FROM Product Product1  INNER JOIN                                    Printer ON Product1.model = Printer.model                               GROUP BY Product1.maker                               )       ) AS result GROUP BY result.maker;

    Схема