CREATE TABLE Branch(
    Id char(8) PRIMARY KEY,
    Name varchar(40),
    NrEmp INT
)
CREATE TABLE Inventory(
    BookId char(8),
    BranchId char(8)
)
CREATE TABLE Publisher(
    Code char(8) PRIMARY KEY,
    Name varchar(40),
    Location varchar(40)
)
CREATE TABLE Author(
    Id char(8) PRIMARY KEY,
    FirstName varchar(40)
)
CREATE TABLE Wrote(
    BookId char(8),
    AuthorId char(8)
)
CREATE TABLE Book(
    Code char(8) PRIMARY KEY,
    Name varchar(40),
    Title varchar(40),
    Price int,
    Type varchar(10),
    Paperback char(3) CHECK (Paperback IN ('Yes','No')),
    Years varchar(4),
    Units char(5)
)
CREATE TABLE PublishBook(
    IdPublisher char(8),
    IdBook char(8)
)