How to check user registration database for duplicate email address?

[Egor Kotov6832188]

Hell Makoto -

You can make call to DB from server-code without session token, thus you can check whenever the email is in use.

You can make it as a separate service, and call it before making actual signin.

[Makoto]

Hello Egor,

Thank you for your advice.

[Deon]

Hi
None of these links work anymore. Please send links to tutorial on how to o this.
Tried your suggestion in my query.

I get a 400 Bad Request when I add this suggested line to my mapping js.

"where": '{"username": {"$regex": "^' + username + '$", "$options":"i"}}'

[saurabh8122815]

Hi Deon,

Use your email as username in Users collection.So it will auto check user is already exists in database.

[Sayed Programmer King]

greetings to all of you,

I am building an android apps for tuition center management for my final year project using apperyio. i've got some problem with displaying the data from the database into labels. i have successfully mapped the first collections value/data into the label, but the second collection need to be checked for its userid which is same id as in the first collection. else it gives me wrong value.

see the picture here :-

My Database collections

First collection :

Second Collection:-

The way i map it :-

and here is the part where i am stuck :-

here is my android testing output