add balance entity

db/migrate/20210811121726_create_balances.rb

@@ -0,0 +1,13 @@
+# frozen_string_literal: true
+class CreateBalances < ActiveRecord::Migration[6.1]
+  def change
+    create_table(:balances) do |t|
+      t.references(:user, null: false, foreign_key: true)
+      t.references(:currency, null: false, foreign_key: true)
+
+      t.decimal(:amount, precision: 20, scale: 10, null: false, default: 0)
+
+      t.timestamps
+    end
+  end
+end

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 2021_08_11_014107) do
+ActiveRecord::Schema.define(version: 2021_08_11_121726) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -55,6 +55,16 @@ ActiveRecord::Schema.define(version: 2021_08_11_014107) do
     t.index ["reset_password_token"], name: "index_admin_users_on_reset_password_token", unique: true
   end
 
+  create_table "balances", force: :cascade do |t|
+    t.bigint "user_id", null: false
+    t.bigint "currency_id", null: false
+    t.decimal "amount", precision: 20, scale: 10, default: "0.0", null: false
+    t.datetime "created_at", precision: 6, null: false
+    t.datetime "updated_at", precision: 6, null: false
+    t.index ["currency_id"], name: "index_balances_on_currency_id"
+    t.index ["user_id"], name: "index_balances_on_user_id"
+  end
+
   create_table "currencies", force: :cascade do |t|
     t.string "name", null: false
     t.datetime "created_at", precision: 6, null: false
@@ -85,5 +95,7 @@ ActiveRecord::Schema.define(version: 2021_08_11_014107) do
 
   add_foreign_key "active_storage_attachments", "active_storage_blobs", column: "blob_id"
   add_foreign_key "active_storage_variant_records", "active_storage_blobs", column: "blob_id"
+  add_foreign_key "balances", "currencies"
+  add_foreign_key "balances", "users"
   add_foreign_key "user_documents", "users"
 end

db/seeds.rb

@@ -1,8 +1,18 @@
 # frozen_string_literal: true
-# This file should contain all the record creation needed to seed the database with its default values.
-# The data can then be loaded with the bin/rails db:seed command (or created alongside the database with db:setup).
-#
-# Examples:
-#
-#   movies = Movie.create([{ name: 'Star Wars' }, { name: 'Lord of the Rings' }])
-#   Character.create(name: 'Luke', movie: movies.first)
+
+AdminUser.create(email: "admin@example.com", password: "password")
+
+user = User.create!(
+  first_name: "Test",
+  last_name: "User",
+  email: "user@example.com",
+  password: "password"
+)
+
+currency = Currency.create!(name: "CAKE")
+
+Balance.create!(
+  user_id: user.id,
+  currency_id: currency.id,
+  amount: 153124.72088
+)