$5\mathrm{.}7$ LAB $-$ Implement supertype and subtype entities $($Sakila$)$

Refer to the customer and staff tables of the Sakila database. These tables have many columns in common and represent similar entities. Convert the customer and staff entities into subtypes of a new supertype person:

In the center is the person entity, with primary key person$\_$id and additional attributes first$\_$name, last$\_$name, email, active, and last$\_$update. The person entity contains subtype entities staff and customer. The staff entity has primary key person$\_$id and additional attributes picture, username, and password. The customer entity has primary key person$\_$id and additional attribute create$\_$date. Cardinality does not appear after the primary keys and attributes. On the left is the address entity, connected to the person entity by the belongs$\_$to relationship. Belongs$\_$to has cardinality $1(1)$ on the address side and M$(0)$ on the person side. On the right is the store entity, connected to the person entity by the works$\_$at relationship. Works$\_$at has cardinality $1(1)$ on the store side and M$(0)$ on the person side.

The diagram uses Sakila naming conventions. Follow the Sakila conventions for your table and column names:

All lower case

Underscore separator between root and suffix

Foreign keys have the same name as referenced primary key

Implement supertype and subtype entities as person, customer, and staff tables with primary key person$\_$id$.$

Implement attributes as columns:

All columns are NOT NULL.

The person$\_$id columns have data type SMALLINT UNSIGNED.

The last$\_$update and create$\_$date columns have data type TIMESTAMP.

The picture column has data type BLOB.

All other columns have data type VARCHAR$(20).$

Implement the dependency relationships between subtype and supertype entities as foreign keys:

The person$\_$id columns of customer and staff become foreign keys referring to person.

Specify CASCADE actions for both relationships.

Implement the belongs$\_$to and works$\_$at relationships as foreign keys:

belongs$\_$to becomes an address$\_$id foreign key in person referring to address.

works$\_$at becomes a store$\_$id foreign key in staff referring to store.

Specify RESTRICT actions for both relationships.

The address and store tables, with primary keys address$\_$id and store$\_$id$,$ are pre$-$defined in the zyLab environment. Foreign keys must have the same data types as the referenced primary keys:

address$\_$id has data type SMALLINT UNSIGNED.

store$\_$id has data type TINYINT UNSIGNED.

If you execute your solution with the Sakila database, you must first drop customer, staff, and all constraints that refer to these tables. Use the following statements with Sakila only, not in the zyLab environment:

ALTER TABLE payment

DROP CONSTRAINT fk$\_$payment$\_$customer,

DROP CONSTRAINT fk$\_$payment$\_$staff;

ALTER TABLE rental

DROP CONSTRAINT fk$\_$rental$\_$customer,

DROP CONSTRAINT fk$\_$rental$\_$staff;

ALTER TABLE store

DROP CONSTRAINT fk$\_$store$\_$staff;

DROP TABLE customer, staff;