backend.py

import sqlite3


class Database:
    def __init__(self, db):
        self.con = sqlite3.connect(db)
        self.cur = self.con.cursor()
        self.cur.execute(
            "CREATE TABLE IF NOT EXISTS books(id INTEGER PRIMARY KEY,title text,author text,year integer,isbn integer)")
        self.con.commit()

    def insertrecord(self, title, author, year, isbn):
        self.cur.execute("INSERT INTO books VALUES(NULL,?,?,?,?)",
                         (title, author, year, isbn))
        self.con.commit()

    def fetchall(self):
        self.cur.execute("SELECT * FROM books")
        rows = self.cur.fetchall()
        return rows

    def search(self, title="", author="", year="", isbn=""):
        self.cur.execute("SELECT * FROM books WHERE title=? OR author=? OR year=? OR isbn=?",
                         (title, author, year, isbn))
        rows = self.cur.fetchall()
        return rows

    def updaterecord(self, bookid, title="", author="", year="", isbn=""):
        self.cur.execute(
            "UPDATE books SET title=?,author=?,year=?,isbn=? WHERE id=?",
            (title, author, year, isbn, bookid))
        self.con.commit()

    def deleterecord(self, bookid):
        self.cur.execute("DELETE FROM books WHERE id=?", (bookid,))
        self.con.commit()

    def __del__(self):
        self.con.close()