EOS Migrate Smart Contract Demo

Description

When updating a smart contract, it is often necessary to make modifications to structs stored in tables. However, due to the way EOS Smart Contracts work, if there is existing data in a table that gets modified, it will become invalid with the new struct format. This example smart contract shows a method of migrating data from one table to another, allowing the user to modify the old table.

How to Use

- Insert some data (run a few times)
	- `cleos push action CONTRACTNAME insert '{}' -p USERNAME`
- Migrate the data from `items` to `items2`
	- `cleos push action CONTRACTNAME migrate '{"version":1"}' -p USERNAME`
- Modify struct for `items` and deploy new contract
- Migrate the data from `items2` to `items`
	- `cleos push action CONTRACTNAME migrate '{"version":2"}' -p USERNAME`

Building

• cd to 'build' directory
• run the command 'cmake ..'
• run the command 'make'

Deploying

• The built smart contract is under the 'migratedemo' directory in the 'build' directory
• You can then do a 'set contract' action with 'cleos' and point in to the './build/migratedemo' directory

Additions to CMake should be done to the CMakeLists.txt in the './src' directory and not in the top level CMakeLists.txt