You should also probably have addressed questions like how many record you’ll be dealing with, and what sort of data you wish to display for each record. Is this a small number of fixed fields, or freeform data?
Also, what type of hardware you are planning to use to store and retrieve the data, and possibly what type of database you are using in the background.
Is this to be a ‘view only’ solution, or is data editing/input needed?
I would imagine that security would be an requirement in this type of project, and the free version of Blynk doesn’t support individual user logins, or any sort of individual user auditing of actions. If I was assessing a project of this type then security would be the top of my checklist, above functionality, usability and look/feel.
The menu widget is one way to allow selection of records, but I’m not sure about the maximum number of menu items that can be displayed.
The numeric input widget is probably a better option, provided you want to select records based just on ID number.
The rest of the functionality - retrieving the correct record from the database and pushing the required data fields to the app - would need to be handled by whatever device you were running the project on. Probably something like an ESP32 would be needed for this, but it depends what type of database you are querying, how many records that has, and what quantity of data you wish to retrieve and push to the app.
This isn’t primarily what Blynk is designed for, so it really depends on what you’re wanting the app to do.