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/*
mysql> select * from Books;
+--------+-----------+---------+
| BookID | BookName | InStock |
+--------+-----------+---------+
| 1 | Poet | 1934 |
| 2 | Ohio | 1919 |
| 3 | Angels | 1966 |
| 4 | Black | 1932 |
| 101 | Writing | 10 |
| 102 | News | 17 |
| 103 | Angels | 23 |
| 104 | Poet | 32 |
| 105 | Dunces | 6 |
| 106 | Solitude | 28 |
| 107 | Postcards | 1992 |
| 108 | The | 1993 |
+--------+-----------+---------+
12 rows in set (0.00 sec)
mysql> UPDATE Books, Orders
-> SET Books.InStock=Books.InStock-Orders.Quantity
-> WHERE Books.BookID=Orders.BookID
-> AND Orders.OrderID=1002;
Query OK, 1 row affected (0.08 sec)
Rows matched: 1 Changed: 1 Warnings: 0
mysql> select * from Books;
+--------+-----------+---------+
| BookID | BookName | InStock |
+--------+-----------+---------+
| 1 | Poet | 1934 |
| 2 | Ohio | 1919 |
| 3 | Angels | 1966 |
| 4 | Black | 1932 |
| 101 | Writing | 9 |
| 102 | News | 17 |
| 103 | Angels | 23 |
| 104 | Poet | 32 |
| 105 | Dunces | 6 |
| 106 | Solitude | 28 |
| 107 | Postcards | 1992 |
| 108 | The | 1993 |
+--------+-----------+---------+
12 rows in set (0.01 sec)
*/
Drop table Books;
Drop table Orders;
CREATE TABLE Books
(
BookID SMALLINT NOT NULL PRIMARY KEY,
BookName VARCHAR(40) NOT NULL,
InStock SMALLINT NOT NULL
)
ENGINE=INNODB;
CREATE TABLE Orders
(
OrderID SMALLINT NOT NULL PRIMARY KEY,
BookID SMALLINT NOT NULL,
Quantity TINYINT (40) NOT NULL DEFAULT 1,
DateOrdered TIMESTAMP,
FOREIGN KEY (BookID) REFERENCES Books (BookID)
)
ENGINE=INNODB;
INSERT INTO Orders VALUES (1001, 103, 1, '2004-01-12 12:30:00'),
(1002, 101, 1, '2001-02-12 12:31:00'),
(1003, 103, 2, '2002-03-12 12:34:00'),
(1004, 104, 3, '2003-04-12 12:36:00'),
(1005, 102, 1, '2004-05-12 12:41:00'),
(1006, 103, 2, '2001-06-12 12:59:00'),
(1007, 101, 1, '2002-07-12 13:01:00'),
(1008, 103, 1, '2003-08-12 13:02:00'),
(1009, 102, 4, '2004-09-12 13:22:00'),
(1010, 101, 2, '2005-11-12 13:30:00'),
(1011, 103, 1, '2006-12-12 13:32:00'),
(1012, 105, 1, '2001-02-12 13:40:00'),
(1013, 106, 2, '2002-04-12 13:44:00'),
(1014, 103, 1, '2003-06-12 14:01:00'),
(1015, 106, 1, '2005-01-12 14:05:00'),
(1016, 104, 2, '2003-11-12 14:28:00'),
(1017, 105, 1, '2002-03-12 14:31:00'),
(1018, 102, 1, '2001-05-12 14:32:00'),
(1019, 106, 3, '2003-07-12 14:49:00'),
(1020, 103, 1, '2004-01-12 14:51:00');
INSERT INTO Books VALUES (101, 'Writing', 12),
(102, 'News', 17),
(103, 'Angels', 23),
(104, 'Poet', 32),
(105, 'Dunces', 6),
(106, 'Solitude', 28);
select * from Books;
UPDATE Books, Orders
SET Books.InStock=Books.InStock-Orders.Quantity
WHERE Books.BookID=Orders.BookID
AND Orders.OrderID=1002;
select * from Books;
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