One-to-many relation data implementation

Sway
1

I would like to implement a one-to-many data structure but from what I read a classic key to array solution is not possible, I have also thought about having a nested StorageVec which however I am not sure is the best way. Would anyoe know a better workaround?

2

Hi again @timotejGerzelj this should be possible try this! Additionally take a look at this forum post which I think might be helpful for you. Is there a way to assign StorageVec inside a struct and then the struct will be used in maps.


use std::storage::storage_vec::*;

storage {
    map: StorageMap<Address, StorageVec<u64>> = StorageMap {},
}

...

toolchain version I’m running

active toolchain
-----------------
latest-aarch64-apple-darwin (default)
  forc : 0.42.0
    - forc-client
      - forc-deploy : 0.42.0
      - forc-run : 0.42.0
    - forc-doc : 0.42.0
    - forc-explore : 0.28.1
    - forc-fmt : 0.42.0
    - forc-index : 0.17.3
    - forc-lsp : 0.42.0
    - forc-tx : 0.42.0
    - forc-wallet : 0.2.3
  fuel-core : 0.18.3
  fuel-indexer : 0.17.3

fuels versions
---------------
forc : 0.43
forc-wallet : 0.43.0
3

Hi @calldelegation thanks again for a response! The reason I thought this type of data-structure is not possible is because of this post here since I was receiving the same error. Could you show me how to update the StorageVec in StorageMap in this case if you dont mind?

4

Yes ofcourse! Assuming you’re on the latest version of the toolchain try something like this:

contract;

use std::storage::storage_vec::*;

storage {
    map: StorageMap<u64, StorageVec<u64>> = StorageMap {},
}

abi MyContract {
    #[storage(read, write)]
    fn insert_function(id: u64);

    #[storage(read, write)]
    fn push_function(id: u64);
}

impl MyContract for Contract {
    #[storage(read, write)]
    fn insert_function(id: u64) {
        let nums: StorageVec<u64> =  StorageVec {};
        storage.map.insert(id, nums);
    }

    #[storage(read, write)]
    fn push_function(id: u64) {
        storage.map.get(id).push(100); 
        // Manipulating vecs inside a mapping (.pop(), .remove() etc.)
    }
}

Theres a ton of helper functions other than .push for you to manipulate the StorageVecs here

1 Like
5

@calldelegation once again thank you! You really are helping me a lot!

1 Like
6

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