I creating dApp and I want to add some sort of registration pannel(add nickname to wallet address) and its nessesary to store this data on db (public wallet address, nickname, email(optionally)). So can I make a function which can add this feature?

1 Answer 1


If you have somewhat complex data that you expect to be used mostly every time I would suggest mapping address to an object.

Declare the object:

struct registration = {
    string nickname; 
    string email;

Then create the mapping:

mapping(address -> registration) database;

You can set the data by calling:

database[targetAddress].nickname = newNickname;
database[targetAddress].email = newEmail; // leave black to keep the initialization value ""


database[targetAddress] = registration(newNickname, newEmail);
database[targetAddress] = registration(newNickname, ); // if you wanted to initialize to "" in this case

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