DROP TABLE IF EXISTS customers; DROP TABLE IF EXISTS orders; DROP TABLE IF EXISTS order_details; DROP TABLE IF EXISTS items; DROP TABLE IF EXISTS artists; DROP TABLE IF EXISTS employees;

-- create tables

CREATE TABLE customers

( customer_id INT , customer_first_name VARCHAR(20), customer_last_name VARCHAR(20) NOT NULL, customer_address VARCHAR(50) NOT NULL, customer_city VARCHAR(20) NOT NULL, customer_state CHAR(2) NOT NULL, customer_zip CHAR(5) NOT NULL, customer_phone CHAR(10) NOT NULL, customer_fax CHAR(10), CONSTRAINT customers_pk PRIMARY KEY (customer_id)

);

CREATE TABLE artists

( artist_id INT NOT NULL, artist_name VARCHAR(30), CONSTRAINT artist_pk PRIMARY KEY (artist_id)

);

CREATE TABLE items

( item_id INT NOT NULL, title VARCHAR(50) NOT NULL, artist_id INT NOT NULL, unit_price DECIMAL(9,2) NOT NULL, CONSTRAINT items_pk PRIMARY KEY (item_id), CONSTRAINT items_fk_artists FOREIGN KEY (artist_id) REFERENCES artists (artist_id) );

CREATE TABLE employees

( employee_id INT NOT NULL, last_name VARCHAR(20) NOT NULL, first_name VARCHAR(20) NOT NULL, manager_id INT , CONSTRAINT employees_pk PRIMARY KEY (employee_id), CONSTRAINT emp_fk_mgr FOREIGN KEY (manager_id) REFERENCES employees(employee_id) );

CREATE TABLE orders

( order_id INT NOT NULL, customer_id INT NOT NULL, order_date DATE NOT NULL, shipped_date DATE, employee_id INT, CONSTRAINT orders_pk PRIMARY KEY (order_id), CONSTRAINT orders_fk_customers FOREIGN KEY (customer_id) REFERENCES customers (customer_id), CONSTRAINT orders_fk_employees FOREIGN KEY (employee_id) REFERENCES employees (employee_id)

);

CREATE TABLE order_details

( order_id INT NOT NULL, item_id INT NOT NULL, order_qty INT NOT NULL, CONSTRAINT order_details_pk PRIMARY KEY (order_id, item_id), CONSTRAINT order_details_fk_orders FOREIGN KEY (order_id) REFERENCES orders (order_id), CONSTRAINT order_details_fk_items FOREIGN KEY (item_id) REFERENCES items (item_id)

);

-- insert rows into tables

INSERT INTO customers VALUES

(1,'Korah','Blanca','1555 W Lane Ave','Columbus','OH','43221','6145554435','6145553928'),

(2,'Yash','Randall','11 E Rancho Madera Rd','Madison','WI','53707','2095551205','2095552262'),

(3,'Johnathon','Millerton','60 Madison Ave','New York','NY','10010','2125554800',NULL),

(4,'Mikayla','Davis','2021 K Street Nw','Washington','DC','20006','2025555561',NULL),

(5,'Kendall','Mayte','4775 E Miami River Rd','Cleves','OH','45002','5135553043',NULL),

(6,'Kaitlin','Hostlery','3250 Spring Grove Ave','Cincinnati','OH','45225','8005551957','8005552826'),

(7,'Derek','Chaddick','9022 E Merchant Wy','Fairfield','IA','52556','5155556130',NULL),

(8,'Deborah','Davis','415 E Olive Ave','Fresno','CA','93728','5595558060',NULL),

(9,'Karina','Lacy','882 W Easton Wy','Los Angeles','CA','90084','8005557000',NULL),

(10,'Kurt','Nickalus','28210 N Avenue Stanford','Valencia','CA','91355','8055550584','055556689'),

(11,'Kelsey','Eulalia','7833 N Ridge Rd','Sacramento','CA','95887','2095557500','2095551302'),

(12,'Anders','Rohansen','12345 E 67th Ave NW','Takoma Park','MD','24512','3385556772',NULL),

(13,'Thalia','Neftaly','2508 W Shaw Ave','Fresno','CA','93711','5595556245',NULL),

(14,'Gonzalo','Keeton','12 Daniel Road','Fairfield','NJ','07004','2015559742',NULL),

(15,'Ania','Irvin','1099 N Farcourt St','Orange','CA','92807','7145559000',NULL),

(16,'Dakota','Baylee','1033 N Sycamore Ave.','Los Angeles','CA','90038','2135554322',NULL),

(17,'Samuel','Jacobsen','3433 E Widget Ave','Palo Alto','CA','92711','4155553434',NULL),

(18,'Justin','Javen','828 S Broadway','Tarrytown','NY','10591','8005550037',NULL),

(19,'Kyle','Marissa','789 E Mercy Ave','Phoenix','AZ','85038','9475553900',NULL),

(20,'Erick','Kaleigh','Five Lakepointe Plaza, Ste 500','Charlotte','NC','28217','7045553500',NULL),

(21,'Marvin','Quintin','2677 Industrial Circle Dr','Columbus','OH','43260','6145558600','6145557580'),

(22,'Rashad','Holbrooke','3467 W Shaw Ave #103','Fresno','CA','93711','5595558625','5595558495'),

(23,'Trisha','Anum','627 Aviation Way','Manhatttan Beach','CA','90266','3105552732',NULL),

(24,'Julian','Carson','372 San Quentin','San Francisco','CA','94161','6175550700',NULL),

(25,'Kirsten','Story','2401 Wisconsin Ave NW','Washington','DC','20559','2065559115',NULL);

INSERT INTO artists(artist_id,artist_name) VALUES

(10, 'Umani'), (11, 'The Ubernerds'), (12, 'No Rest For The Weary'), (13, 'Burt Ruggles'), (14, 'Sewed the Vest Pocket'), (15, 'Jess & Odie'), (16, 'Onn & Onn');

INSERT INTO items (item_id,title,artist_id,unit_price) VALUES

(1,'Umami In Concert',10,17.95),

(2,'Race Car Sounds',11,13),

(3,'No Rest For The Weary',12,16.95),

(4,'More Songs About Structures and Comestibles',12,17.95),

(5,'On The Road With Burt Ruggles',13,17.5),

(6,'No Fixed Address',14,16.95),

(7,'Rude Noises',15,13),

(8,'Burt Ruggles: An Intimate Portrait',13,17.95),

(9,'Zone Out With Umami',10,16.95),

(10,'Etcetera',16,17);

INSERT INTO employees VALUES

(1,'Smith', 'Cindy', null),

(2,'Jones', 'Elmer', 1),

(3,'Simonian', 'Ralph', 2), (9,'Locario', 'Paulo',1), (8,'Leary', 'Rhea',9), (4,'Hernandez','Olivia',9),

(5,'Aaronsen', 'Robert',4),

(6,'Watson', 'Denise',8),

(7,'Hardy', 'Thomas',2);

INSERT INTO orders VALUES

(19, 1, '2012-10-23', '2012-10-28', 6),

(29, 8, '2012-11-05', '2012-11-11', 6),

(32, 11, '2012-11-10', '2012-11-13', NULL),

(45, 2, '2012-11-25', '2012-11-30', NULL),

(70, 10, '2012-12-28', '2013-01-07', 5),

(89, 22, '2013-01-20', '2013-01-22', 7),

(97, 20, '2013-01-29', '2013-02-02', 5),

(118, 3, '2013-02-24', '2013-02-28', 7),

(144, 17, '2013-03-21', '2013-03-29', NULL),

(158, 9, '2013-04-04', '2013-04-20', NULL),

(165, 14, '2013-04-11', '2013-04-13', NULL),

(180, 24, '2013-04-25', '2013-05-30', NULL),

(231, 15, '2013-06-14', '2013-06-22', NULL),

(242, 23, '2013-06-24', '2013-07-06', 3),

(264, 9, '2013-07-15', '2013-07-18', 6),

(298, 18, '2013-08-18', '2013-09-22', 3),

(321, 2, '2013-09-09', '2013-10-05', 6),

(381, 7, '2013-11-08', '2013-11-16', 7), (413, 17, '2013-12-05', '2014-01-11', 7),

(442, 5, '2013-12-28', '2014-01-03', 5),

(479, 1, '2014-01-30', '2014-03-03', 3),

(491, 16, '2014-02-08', '2014-02-14', 5),

(523, 3, '2014-03-07', '2014-03-15', 3),

(548, 2, '2014-03-22', '2014-04-18', NULL),

(550, 17, '2014-03-23', '2014-04-03', NULL),

(601, 16, '2014-04-21', '2014-04-27', NULL),

(607, 20, '2014-04-25', '2014-05-04', NULL),

(624, 2, '2014-05-04', '2014-05-09', NULL),

(627, 17, '2014-05-05', '2014-05-10', NULL),

(630, 20, '2014-05-08', '2014-05-18', 7),

(651, 12, '2014-05-19', '2014-06-02', 7),

(658, 12, '2014-05-23', '2014-06-02', 7),

(687, 17, '2014-06-05', '2014-06-08', NULL),

(693, 9, '2014-06-07', '2014-06-19', NULL),

(703, 19, '2014-06-12', '2014-06-19', 7),

(778, 13, '2014-07-12', '2014-07-21', 7),

(796, 17, '2014-07-19', '2014-07-26', 5),

(800, 19, '2014-07-21', '2014-07-28', NULL),

(802, 2, '2014-07-21', '2014-07-31', NULL),

(824, 1, '2014-08-01', NULL, NULL),

(827, 18, '2014-08-02', NULL, NULL),

(829, 9, '2014-08-02', NULL, NULL);

INSERT INTO order_details VALUES

(381,1,1),(601,9,1), (442,1,1), (523,9,1),

(630,5,1), (778,1,1), (693,10,1), (118,1,1),

(264,7,1), (607,10,1), (624,7,1), (658,1,1),

(800,5,1), (158,3,1), (321,10,1), (687,6,1),

(827,6,1), (144,3,1),

(479,1,2),

(630,6,2),(796,5,1),(97,4,1), (601,5,1),

(800,1,1), (29,10,1), (70,1,1),

(165,4,1), (180,4,1), (231,10,1),

(413,10,1), (491,6,1),

(607,3,1), (651,3,1), (703,4,1),

(802,3,1), (824,7,2),

(829,1,1), (550,4,1), (796,7,1), (693,6,1), (29,3,1), (32,7,1), (242,1,1),

(298,1,1), (479,4,1), (548,9,1), (627,9,1),

(778,3,1),

(19,5,1), (89,4,1),

(242,6,1), (264,4,1), (550,1,1),

(693,7,3), (824,3,1), (829,5,1), (829,9,1);

Use an ALTER TABLE statement to update the customers table so that the Primary Key field is an auto-increment field, then create TWO insert statements to test proper operation, using your own first and last name for one (and a name of your choice for the second one), and any data you care to imagine for the remaining fields.

IMPORTANT NOTE: When using a LOCAL copy of MySQL, if you attempt to simply issue the ALTER TABLE command you have composed by itself, you should receive an error similar to the following (try it for yourself!).

ERROR 1833: Cannot change column 'customer_id': used in a foreign key constraint 'orders_fk_customers' of table 'om.orders'

(Note EDUPE will not give this error message, however you should still follow the CORRECT procedure as discussed here to complete this problem).

The reason for this is that you are attempting to alter data in one column that has a defined PK:FK relationship to a field in another table. Referential Integrity rules prevent this. So, how do you resolve such a problem?

One approach to solving this dilemma is to turn off the foreign key checks that implement referential integrity rules. However, the danger here is that other users and processes operating on the database while these constraints are suspended could create or modify data in a way that compromises integrity. We can solve this second problem by preventing other users and processes from altering the data in the table in which we are working until we have turned the foreign key checks back on. We therefore need to construct a script that does the following.

Locks the customer table -- lock table customers write;

Turns off FK checks -- set foreign_key_checks = 0;

Alters the table to add the auto_increment feature to the PK field

Turns FK checks back on -- set foreign_key_checks = 1;

Unlocks the customer table -- unlock tables;

It is VERY important to consider that altering tables can require a bit of time for very large tables, and that while the table is locked, other users and processes cannot operate. Consequently, this kind of modification should not be done during peak operating hours in a production operation (as a student in a lab exercise, working on your own database, you may do this at any time) but ideally in hours during which the business does not normally operate. In cases where round-the-clock, high availability of a database is required, other approaches may be required. Addressing this problem in a high-availability, high-demand environment is an advanced topic, study of which is outside the scope of this course. Use the outline below to construct your script. Show all commands in your answer sheet along with the output of the commands.

lock table customers write;

set foreign_key_checks = 0;

-- Replace this comment with your ALTER TABLE command to add the auto_increment feature to the PK field

set foreign_key_checks = 1;

unlock tables;

--statements to insert two rows into the table

--verify auto_increment with a select statement