ADD model ProjectCategory

app/models/project_category.rb

@@ -0,0 +1,2 @@
+class ProjectCategory < ApplicationRecord
+end

db/migrate/20191218015959_create_project_categories.rb

@@ -0,0 +1,17 @@
+class CreateProjectCategories < ActiveRecord::Migration[5.2]
+  def change
+    create_table :project_categories do |t|
+      t.string :name
+      t.integer :position
+      t.integer :projects_count, :default => 0
+
+      t.timestamps
+    end
+
+    names = %w(大数据 机器学习 深度学习 人工智能 量子计算 智慧医疗 自动驾驶 其他)
+    names.each do |name|
+      ProjectCategory.find_or_create_by!(name: name)
+    end
+
+  end
+end