Store N key value pairs

Question

I have a scenario where I need to store N no. of document hashes in a smart contract with some key(id). And also fetch the particular document hash by it's key. Any help on designing the structure for storing would be appreciated. Thanks

Answer 1

Here's a rough version:

pragma solidity ^0.4.24;

contract Test {

    mapping(uint256 => string) hashes;

    function addDoc(uint256 id, string hash) public {
        hashes[id] = hash;
    }

    function getDoc(uint256 id) public view returns(string) {
        return hashes[id];
    }
}

Here you can store and retrieve the hashes based on a uint256 id. The mapping will store as many id<->hash values as you need.

What you should do next is change the string types to be something else (bytes of some length) and consider adding some mass-add function if you need to store multiple hashes at the same time.