Count Unique Entries in Database to Graph

LetsDoIt
Wed, 23 Apr 2025 12:05:54 +0000
General

Hi folks,

I've resurrected an old project and I need a little help please.

Long story short, I've installed Node Red on a phone. I've managed to get it to use a motion detection app to take photos and put them in a folder. Node Red then uses an API to upload the photos to an object recognition site which returns a JSON detailing what it "sees". I am going to point this as my bird feeder to identify the visitors. I have got the system to email me photos and even "text to speech" announce what is on the feeder.

Phase 2 is to write each visitor into a database with fields being as follows:

Time_Taken (The time the alert was detected)
Visitor_Name (The name returned from the API)
Photo (Base64 copy of the photo taken)

I would then like to count each of entry for a unique Visitor_Name and pass this to the dashboard so I can have a bar graph showing the number of visits for each type of bird.

For example, a robin gets captured so it is logged in the database. It might come back again so it is logged again. The graph would then have a bar for "Robin" with a value of 2. A Starling then arrives and is logged in the database and the graph automatically has a bar for "Starling" with a value of 1.

I don't know anything about Databases in Node Red, so my questions are as follows:

1. How do I set up a persistent database file which would survive reboots?

2. How do I count the unique values entered into the database and pass the unique names and the number of times they exist over to the dashboard?

Hope this all makes sense - please ask if I'm talking gibberish!

Cheers, K.

TL;DR : How do I count unique entries in a database and dynamically update a graph on the dashboard with the name and count value, even when new unique values are added?

2 posts - 2 participants