create articles table, model and add validation

app/models/article.rb

@@ -0,0 +1,6 @@
+class Article < ActiveRecord::Base
+
+ validates :title , presence: true, length: { minimum: 3, maximum: 50 }
+ validates :description, presence: true, length: { minimum: 10, maximum: 300}
+
+end

db/migrate/20180405102959_create_articles.rb

@@ -0,0 +1,7 @@
+class CreateArticles < ActiveRecord::Migration
+ def change
+ create_table :articles do |t|
+ t.string :title
+ end
+ end
+end

db/migrate/20180405104833_add_description_to_articles.rb

@@ -0,0 +1,7 @@
+class AddDescriptionToArticles < ActiveRecord::Migration
+ def change
+ add_column :articles, :description, :text
+ add_column :articles, :created_at, :datetime
+ add_column :articles, :updated_at, :datetime
+ end
+end

db/schema.rb

@@ -0,0 +1,23 @@
+# encoding: UTF-8
+# This file is auto-generated from the current state of the database. Instead
+# of editing this file, please use the migrations feature of Active Record to
+# incrementally modify your database, and then regenerate this schema definition.
+#
+# Note that this schema.rb definition is the authoritative source for your
+# database schema. If you need to create the application database on another
+# system, you should be using db:schema:load, not running all the migrations
+# from scratch. The latter is a flawed and unsustainable approach (the more migrations
+# you'll amass, the slower it'll run and the greater likelihood for issues).
+#
+# It's strongly recommended that you check this file into your version control system.
+
+ActiveRecord::Schema.define(version: 20180405104833) do
+
+ create_table "articles", force: :cascade do |t|
+ t.string "title"
+ t.text "description"
+ t.datetime "created_at"
+ t.datetime "updated_at"
+ end
+
+end