Auto increament in Entry field. in tkinter GUI

[menator01]

This is with sqlite3 but queries are the same

#! /usr/bin/env python3
import sqlite3
import tkinter as tk

conn = sqlite3.connect('test.db')
cursor = conn.cursor()
cursor.execute('drop table if exists test_table')
conn.commit()

conn = sqlite3.connect('test.db')
cursor = conn.cursor()
table = '''create table test_table(
            id integer primary key autoincrement not null,
            name varchar(100) not null
        )'''
conn.execute(table)
conn.commit()

names = [(1,'tom'), (2, 'harry'), (3, 'john'),(4, 'mary'), (5, 'pam')]

conn = sqlite3.connect('test.db')
cursor = conn.cursor()
cursor.executemany('insert into test_table (id, name) values (?, ?)', names)
conn.commit()

count = cursor.execute('select count(*) from test_table')
next_num = count.fetchall()[0][0]
conn.close()

root = tk.Tk()
var = tk.IntVar()
var.set(next_num+1)
field1 = tk.Entry(root, text=var, width=5)
field1.grid(column=0, row=0)

field2 = tk.Entry(root, width=20)
field2.grid(column=1, row=0)

label = tk.Label(root, text=f'Current entries: {var.get()-1}')
label.grid(column=0, row=1, sticky='w')

btn = tk.Button(root, text='Submit')
btn.grid(column=1, row=1, sticky='e')
root.mainloop()