Write at least 8 queries on your database, using the select-from-where construct of SQL. All of your queries should exhibit “interesting” features of SQL: queries over more than one relation, sub-queries (you may have at most one query involving a single relation, at least one that involves two relations and at least one that involves three relations), grouping and aggregation.

create table Student(
Student_ID int primary key,
FName varchar(45),
LName varchar(45),
Contact_Num char(20),
Email varchar(45),
Borrow_ID int,
UNIQUE (Borrow_ID)
);

create table Books(
ISBN int primary key,
Book_Title varchar(45),
Book_Edition int,
Publication_Year int,
Language varchar(45),
UNIQUE (Book_Title)
);

create table Branch(
Branch_ID int primary key,
Branch_Name varchar(45),
B_Location varchar(45),
B_Email varchar(45),
B_ContactNum char(20)
);

create table Author(
FName varchar(10) primary key,
LName varchar(45),
Book_Title varchar(45),
Book_Date date,
foreign key (Book_Title) references Books(Book_Title)
);

create table Staff(
Staff_ID int primary key,
FName varchar(45),
LName varchar(45),
S_Num char(20),
Branch_ID int,
foreign key (Branch_ID) references Branch(Branch_ID)
);

create table Borrow_Book(
Borrower_ID int primary key,
Book_ID int,
Borrowed_From_Date date,
Borrowed_To_Date date,
Issued_ID int,
foreign key (Borrower_ID) references Student(Borrow_ID),
foreign key (Book_ID) references Books(ISBN),
foreign key (Issued_ID) references Staff(Staff_ID),
unique(Book_ID)
);

create table Issued_Books(
Issued_ID int primary key,
Book_Title varchar(45),
Book_ID int,
Date_Issued date,
foreign key (Book_Title) references Books(Book_Title),
foreign key (Book_ID) references Books(ISBN),
foreign key (Issued_ID) references Staff(Staff_ID),
UNIQUE(Book_Title),
unique(Book_ID)
);

create table Copies_of_Books(
Book_ID int primary key,
Book_Title varchar(45),
Num_Of_Copies_Actual int,
Num_Of_Copies_Current int,
foreign key (Book_Title) references Books(Book_Title),
foreign key (Book_ID) references Books(ISBN)
);

create table Return_Books(
Book_ID int primary key,
Book_Title varchar(45),
Borrower_ID int,
Borrowed_To_Date date,
Actual_Return_Date date,
foreign key (Book_ID) references Issued_Books(Book_ID),
foreign key (Book_Title) references Issued_Books(Book_Title),
foreign key (Borrower_ID) references Borrow_Book(Borrower_ID)
);

create table untarnished_Books(
Book_ID int primary key,
Book_Title varchar(45),
Issued_ID int,
Condition_out_of_ten int default'0',
foreign key (Book_ID) references Issued_Books(Book_ID),
foreign key (Book_Title) references Issued_Books(Book_Title),
foreign key (Issued_ID) references Issued_Books(Issued_ID)
)