EOS Contract - CRUD Example

This is a very minimal example of an EOS Smart Contract that will do 4 simple things. Create, Read, Update, and Destroy. This contract is basically a simple database without any great features. Each "record" includes an id, user, and data which is a string.

Setup

This step requires you to have a EOS blockchain server already setup and running. You can follow the Tutorial to get up and running.

// run the EOS server with --contracts-console
nodeos -e -p eosio --plugin eosio::chain_api_plugin --plugin eosio::history_api_plugin --contracts-console

Then clone this repo.

git clone https://github.com/element-group/eoscrud
cd eoscrud

Build Contract

eosiocpp -o eoscrud.wast eoscrud.cpp
eosiocpp -g eoscrud.abi eoscrud.cpp

Deploy Contract

cleos create account eosio eoscrud <EOS address here> 
cleos set contract eoscrud ../eoscrud -p eoscrud

Contract Interaction

While interacting with the contract, you'll see the print logs inside the EOS server console.

Create (id, user, data)

cleos push action eoscrud create '[1, "user", "oh heyyy this is new"]' -p eoscrud

// [(eoscrud,create)->eoscrud]: CONSOLE OUTPUT BEGIN =====================
// Hello, userCreated with data: oh heyyy this is new
// [(eoscrud,create)->eoscrud]: CONSOLE OUTPUT END   =====================

Read (id)

cleos push action eoscrud read '[1]' -p eoscrud

// [(eoscrud,read)->eoscrud]: CONSOLE OUTPUT BEGIN =====================
// Data: oh heyyy this is new
// [(eoscrud,read)->eoscrud]: CONSOLE OUTPUT END   =====================

Update (id, data)

cleos push action eoscrud update '[1, "this is updated"]' -p eoscrud

// [(eoscrud,update)->eoscrud]: CONSOLE OUTPUT BEGIN =====================
// Data: this is updated
// [(eoscrud,update)->eoscrud]: CONSOLE OUTPUT END   =====================

Destroy (id)

cleos push action eoscrud destroy '[1]' -p eoscrud

// [(eoscrud,destroy)->eoscrud]: CONSOLE OUTPUT BEGIN =====================
// Record Destroyed: 1
// [(eoscrud,destroy)->eoscrud]: CONSOLE OUTPUT END   =====================