computer_firm_schema.sql

CREATE TABLE product (
    maker VARCHAR(10) NOT NULL,
    model VARCHAR(50) NOT NULL PRIMARY KEY,
    type VARCHAR(50) NOT NULL
);

CREATE TABLE pc (
    code INT NOT NULL PRIMARY KEY,
    model VARCHAR(50) NOT NULL,
    speed SMALLINT NOT NULL,
    ram SMALLINT NOT NULL,
    hd REAL NOT NULL,
    cd VARCHAR(10) NOT NULL,
    price DECIMAL(8,4),
    CONSTRAINT FK_pc_product FOREIGN KEY (model) REFERENCES product(model)
);

CREATE TABLE laptop (
    code INT NOT NULL PRIMARY KEY,
    model VARCHAR(50) NOT NULL,
    speed SMALLINT NOT NULL,
    ram SMALLINT NOT NULL,
    hd REAL NOT NULL,
    price DECIMAL(8,4),
    screen TINYINT NOT NULL,
    CONSTRAINT FK_laptop_product FOREIGN KEY (model) REFERENCES product(model)
);

CREATE TABLE printer (
    code INT NOT NULL PRIMARY KEY,
    model VARCHAR(50) NOT NULL,
    color CHAR(1) NOT NULL,
    type VARCHAR(10) NOT NULL,
    price DECIMAL(8,4),
    CONSTRAINT FK_printer_product FOREIGN KEY (model) REFERENCES product(model)
);