If you have a sqlite3 database with the options in a column "select" and a table e.g. entries, you can do it like here:

import sqlite3
import tkinter as tk

# Create a sqlite3 database with a table 'entries' and column select who have three text values
# [('First selection',), ('Second slection',), ('Third selection',)]

try:
    conn = sqlite3.connect('DropBox_DB.db')
    print("SQLITE3 Version", sqlite3.sqlite_version)

except Error as e:
    print(e)
       
cur = conn.cursor()
cur.execute("SELECT * FROM entries;")
entries = cur.fetchall()

master = tk.Tk()
master.geometry("300x100")  
master.title("Dropdown Example")  

variable = tk.StringVar(master)
variable.set(select[0]) 

w = tk.OptionMenu(master, variable, *[x[0] for x in entries])
w.grid()

master.mainloop()

Output: