amos-kibet

Ecto Changesets Crash Course

• In order to insert, update or delete data from the database, Ecto.Repo.insert/2, update/2 and delete/2 require a changeset as their first parameter
• Changesets validate data before being inserted to the database by checking for potential errors, asserting that required fields are passed, asserting that non-empty fields have data, keeping track of changes in the data (think of it as a version control for database transactions), etc

Empty Changeset

iex> %Ecto.Changeset{}
%Ecto.Changeset<action: nil, changes: %{}, errors: [], data: nil, valid?: false>

amos-kibet

-- A game with two players. Player 1 thinks of a secret word
-- and uses its hash, and the game validator script, to lock
-- some funds (the prize) in a pay-to-script transaction output.
-- Player 2 guesses the word by attempting to spend the transaction
-- output. If the guess is correct, the validator script releases the funds.
-- If it isn't, the funds stay locked.
import Control.Monad (void)
import Data.ByteString.Char8 qualified as C
import Data.Map (Map)
import Data.Map qualified as Map