feat: Add APIs for Campaigns (#2175)

db/migrate/20210428135041_campaigns.rb

@@ -0,0 +1,18 @@
+class Campaigns < ActiveRecord::Migration[6.0]
+  def change
+    create_table :campaigns do |t|
+      t.integer :display_id, null: false
+      t.string :title, null: false
+      t.text :description
+      t.text :content, null: false
+      t.integer :sender_id
+      t.boolean :enabled, default: true
+      t.references :account, null: false, foreign_key: true
+      t.references :inbox, null: false, foreign_key: true
+      t.column :trigger_rules, :jsonb, default: {}
+      t.timestamps
+    end
+
+    add_reference :conversations, :campaign, foreign_key: true
+  end
+end

db/migrate/20210428151147_create_triggers_accounts_insert_or_campaigns_insert.rb

@@ -0,0 +1,28 @@
+# This migration was auto-generated via `rake db:generate_trigger_migration'.
+# While you can edit this file, any changes you make to the definitions here
+# will be undone by the next auto-generated trigger migration.
+
+class CreateTriggersAccountsInsertOrCampaignsInsert < ActiveRecord::Migration[6.0]
+  def up
+    create_trigger('camp_dpid_before_insert', generated: true, compatibility: 1)
+      .on('accounts')
+      .name('camp_dpid_before_insert')
+      .after(:insert)
+      .for_each(:row) do
+      "execute format('create sequence IF NOT EXISTS camp_dpid_seq_%s', NEW.id);"
+    end
+
+    create_trigger('campaigns_before_insert_row_tr', generated: true, compatibility: 1)
+      .on('campaigns')
+      .before(:insert)
+      .for_each(:row) do
+      "NEW.display_id := nextval('camp_dpid_seq_' || NEW.account_id);"
+    end
+  end
+
+  def down
+    drop_trigger('camp_dpid_before_insert', 'accounts', generated: true)
+
+    drop_trigger('campaigns_before_insert_row_tr', 'campaigns', generated: true)
+  end
+end