Notify User if Username or Password Already Exists in TinyDB

Hello, everyone! Hope you are having a great day! I have made a login and sign-up page in MIT app inventor using the tutorial below. I want to know how I can notify the user if a username or password already exists in TinyDB. How can I do this? Please help me, I need this ASAP! Thank you in advance!

This question has been answered before. Please search the forum next time before opening a topic.

Hint: use call TinyDB GetTags. Read about TinyDB here.

Sorry, but that does not answer my question as I do not know how to use the 'call TinyDB GetTags'. Could you please provide me an image of blocks, an .aia file, or a tutorial?

Could you please search the forum as the answers are already there?

Before making apps you should learn the basics of the components you are using. Read about TinyDB at the link I gave you.

Also, you do not show any blocks that relate to username or password, as per your question. Duplicate passwords should not be an issue, and it would not be wise to tell a user that the password they just typed is already in use!! Test only for username, ensure that is unique.

Will there be many people all using the same device?

No, many people will be using the same device.

A very good way to learn App Inventor is to read the free Inventor's Manual here in the AI2 free online eBook ... the links are at the bottom of the Web page. The book 'teaches' users how to program with AI2 blocks.
There is a free programming course here and the aia files for the projects in the book are here:
How to do a lot of basic things with App Inventor are described here: .

Also do the tutorials to learn the basics of App Inventor, then try something and follow the Top 5 Tips: How to learn App Inventor


Trying to push the limits! Snippets, Tutorials and Extensions from Pura Vida Apps by icon24 Taifun.