How to display a BLOB image stored in my SQLite database?

Question

I have a CRUD form with entries and 4 button for deleting, updating, creating, getting values from my database, I want to implement another button to open an imagen which is binded to my id entry also able to works with my deleting, updating, creating, getting buttons, I've been trying to use BLOB and I'm able to save an image in my database as BLOB. Actually I understand that I need to create textvariables for my entries like 'idvar = StringVar() , namevar = Stringvar()..., etc', So I'm not sure how to do it for an image label in order to work with my CRUD buttons deleting, updating, creating, getting

This is my code I got so far and it's working well saving images into my photos columns:

from tkinter import *
import sqlite3

top = Tk()
top.configure(width='444', heigh='400')

conn = sqlite3.connect('test.db')
c = conn.cursor()

def enterdata():
    id = 'hello'
    photo = convert_pic()
    c.execute('INSERT INTO test (id, photo) VALUES (?, ?)', (id, photo)) #Here my id has integer value and my photo has BLOB value in my database 
    conn.commit()

def convert_pic():
    filename = 'images/image6.jpg'
    with open(filename, 'rb') as file:
        photo = file.read()
    return photo


btn = Button(top, text='save photo', command=enterdata)
btn.place(x='100', y='111')


mainloop()

Answer 1

Now that you have the BLOB you can use io.BytesIO. I will create an example to demonstrate, like:

from PIL import Image, ImageTk
from io import BytesIO

def show(data):
    img_byte = BytesIO(data)
    img = ImageTk.PhotoImage(Image.open(img_byte))
    Label(root,image=img).pack()
    root.image = img # Keep a reference

So now you can query the database and fetch the value:

def fetch():
    c = con.cursor()
    id = 1 # Any id
    c.execute('SELECT photo FROM test where id=?',(id,))
    data = c.fetchall()[0][0] # Get the blob data
    show(data) # Call the function with the passes data

This will show the image in a label in the root window for the entered id.