Nested mapping in solidity

Question

this code require two input(_Id,_name) to get age i need to get name and age from input id only

// SPDX-License-Identifier: GPL-3.0
pragma solidity >=0.7.0 <0.9.0;
contract nestmap
{
    mapping(uint256=>mapping(string=>uint256)) public User;
    function adduser(uint256 _Id,string memory _name, uint256 _age)public {
         User[_Id][_name]=_age;
    }
}
function user(uint256 _Id,string memory _name)public view returns(uint256)
    {
        return User[_Id][_name];
    }

Your nested mapping describes a data structure where each id has a large number of string keys, and each of those maps to a uint256, so probably not what you want. It's roughtly key1 => key2 => value, hence two keys are requested. I voted for Yongjian's answer. That's probably what you want. — Rob Hitchens, Oct 19 '22 at 21:12

score 2 · Accepted Answer · answered Oct 19 '22 at 20:23

You can try this:

pragma solidity 0.8.7;
contract nestmap {
struct Person{
    uint256 age;
    string name;
}

mapping (uint256 =&gt; Person) public User;

function adduser(uint256 _Id, uint256 _age, string memory _name) public {
     User[_Id].age = _age;
     User[_Id].name = _name;
}

function user(uint256 _Id) public view returns(Person memory) {
    return User[_Id];
}

}

Nested mapping in solidity

1 Answers1