backend.py

import sqlite3
def connect():
    """Set up a connection with the database."""
    conn_obj = sqlite3.connect("books.db")
    cur_obj = conn_obj.cursor()
    cur_obj.execute("CREATE TABLE IF NOT EXISTS "
                    "book (id integer PRIMARY KEY, "
                            "title text, "
                            "author text, "
                            "year integer, "
                            "isbn integer)")
    conn_obj.commit()
    conn_obj.close()
def insert(title, author, year, isbn):
    """Insert entry into database."""
    conn_obj = sqlite3.connect("books.db")
    cur_obj = conn_obj.cursor()
    cur_obj.execute("INSERT INTO book "
                    "VALUES (NULL, ?, ?, ?, ?)", (title, author, year, isbn))
    conn_obj.commit()
    conn_obj.close()

def view():
    """View all database entries."""
    conn_obj = sqlite3.connect("books.db")
    cur_obj = conn_obj.cursor()
    cur_obj.execute("SELECT * FROM book")
    rows = cur_obj.fetchall()
    conn_obj.close()
    return rows

def update(id, title, author, year, isbn):
    """Update a database entry."""
    conn_obj = sqlite3.connect("books.db")
    cur_obj = conn_obj.cursor()
    cur_obj.execute("UPDATE book "
                    "SET title = ?, "
                    "author = ?, "
                    "year = ?, "
                    "isbn = ? "
                    "WHERE id = ?", 
                    (title, author, year, isbn, id))
    conn_obj.commit()
    conn_obj.close()

def delete(d):
    """Delete a database entry."""
    conn_obj = sqlite3.connect("books.db")
    cur_obj = conn_obj.cursor()
    cur_obj.execute("DELETE FROM book WHERE id = ?",(d,))
    conn_obj.commit()
    conn_obj.close()

def search(title = "", author = "", year = "", isbn = ""):
    """Search for a database entry."""
    conn_obj = sqlite3.connect("books.db")
    cur_obj = conn_obj.cursor()
    cur_obj.execute("SELECT * "
                    "FROM book "
                    "WHERE title = ? OR author = ? OR year = ? OR isbn = ?", 
                    (title, author, year, isbn))
    rows = cur_obj.fetchall()
    conn_obj.close()
    return rows
    
connect()