Python Flask, display an image stored as a binary blob in MySQL database

May 22, 2023

I’m trying to display an image that is stored in a LONGBLOB column in a MySQL database, using Flask:

app.py:

@app.route('/get_image', methods=['GET'])
def get_image():
    args = request.args
    image_id = args.get('image_id')

    image = # code for getting image blob from database
    return send_file(image, mimetype='image/png')

HTML code:

<img src="http://127.0.0.1:5000/get_image?image_id=1"/>

When a request for the image is sent, I can see in debugger that the image bytes are retrieved from the database:

However the image is not displayed:

>Solution :

The send_file function expects a path-like or file-like object, not a bytes object. Use BytesIO to give your bytes a file-like interface:

from io import BytesIO

@app.route('/get_image', methods=['GET'])
def get_image():
    args = request.args
    image_id = args.get('image_id')

    image = # code for getting image blob from database

    #                   👇🏿
    return send_file(BytesIO(image), mimetype='image/png')