Added lab_2 files.

1.sql

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+SELECT pc.model, pc.speed, pc.hd FROM PC
+INNER JOIN product
+ON pc.model=product.model
+WHERE pc.hd = 10 AND maker='A' OR pc.hd = 20 AND maker='A'
+ORDER BY pc.speed;

10.sql

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+SELECT type, product.model, MAX(price) AS max_price
+FROM (SELECT model, price 
+	FROM pc
+    UNION SELECT model, price
+    FROM printer
+    UNION SELECT model, price
+    FROM laptop) AS product_any JOIN product ON product_any.model = product.model
+GROUP BY product.model

2.sql

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+SELECT * FROM outcome_o
+WHERE date LIKE '____-__-14%';

3.sql

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+SELECT maker
+FROM product JOIN pc ON pc.model = product.model
+GROUP BY maker 
+	HAVING MIN(speed)>=600;

4.sql

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+SELECT maker
+FROM product LEFT JOIN pc ON pc.model = product.model
+WHERE pc.model is null and type='PC'
+GROUP BY maker;

5.sql

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+SELECT maker
+FROM product 
+WHERE EXISTS (
+	SELECT maker
+	FROM product AS all_products LEFT JOIN pc ON pc.model = all_products.model 
+	WHERE type = 'PC' AND product.maker = all_products.maker
+	GROUP BY maker 
+	 HAVING COUNT(all_products.model) = COUNT(pc.model))
+GROUP BY maker;

6.sql

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+SELECT CONCAT('name: ', name) AS name,
+	   CONCAT('class: ', class) AS class,
+       CONCAT('launched: ', launched) AS launched
+FROM ships

7.sql

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+SELECT maker
+FROM product LEFT JOIN pc ON pc.model = product.model
+WHERE type='PC'
+GROUP BY maker
+	HAVING COUNT(pc.model) BETWEEN 1 AND COUNT(product.model) - 1; 

8.sql

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+SELECT ship,
+	(SELECT classes.country FROM ships JOIN classes ON
+	    outcomes.ship = ships.name AND ships.class = classes.class)  AS country
+FROM outcomes
+WHERE result='sunk' AND
+      (SELECT ships.name FROM ships WHERE outcomes.ship = ships.name) IS NOT NULL;

9.sql

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+SELECT maker,
+       IF(product_pc=0, 'no', CONCAT('yes(', available_pc, ')')) AS creates_pc
+FROM(SELECT maker, CASE WHEN product.type='PC' THEN 1 ELSE 0 END AS
+    product_pc, COUNT(available_models.model) as available_pc
+	FROM product 
+	LEFT JOIN (SELECT model FROM pc) AS available_models ON
+	    available_models.model = product.model
+	GROUP BY maker) AS products_pc
+ORDER BY maker;