Rename epic column state to state_id

Rename epic column state to state_id to be consistent with
issues and merge requests

changelogs/unreleased/issue_10770.yml

+---
+title: Rename epic column state to state_id
+merge_request: 32270
+author:
+type: changed

db/migrate/20190822175441_rename_epics_state_to_state_id.rb

+# frozen_string_literal: true
+
+class RenameEpicsStateToStateId < ActiveRecord::Migration[5.2]
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  disable_ddl_transaction!
+
+  def up
+    rename_column_concurrently :epics, :state, :state_id
+  end
+
+  def down
+    cleanup_concurrent_column_rename :epics, :state_id, :state
+  end
+end

db/post_migrate/20190822185441_cleanup_epics_state_id_rename.rb

+# frozen_string_literal: true
+
+class CleanupEpicsStateIdRename < ActiveRecord::Migration[5.2]
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  disable_ddl_transaction!
+
+  def up
+    cleanup_concurrent_column_rename :epics, :state, :state_id
+  end
+
+  def down
+    rename_column_concurrently :epics, :state_id, :state
+  end
+end

db/schema.rb

@@ -1286,11 +1286,11 @@ ActiveRecord::Schema.define(version: 2019_08_28_083843) do
     t.date "due_date_fixed"
     t.boolean "start_date_is_fixed"
     t.boolean "due_date_is_fixed"
-    t.integer "state", limit: 2, default: 1, null: false
     t.integer "closed_by_id"
     t.datetime "closed_at"
     t.integer "parent_id"
     t.integer "relative_position"
+    t.integer "state_id", limit: 2, default: 1, null: false
     t.index ["assignee_id"], name: "index_epics_on_assignee_id"
     t.index ["author_id"], name: "index_epics_on_author_id"
     t.index ["closed_by_id"], name: "index_epics_on_closed_by_id"

spec/db/schema_spec.rb

@@ -30,7 +30,7 @@ describe 'Database schema' do
     draft_notes: %w[discussion_id commit_id],
     emails: %w[user_id],
     events: %w[target_id],
-    epics: %w[updated_by_id last_edited_by_id start_date_sourcing_milestone_id due_date_sourcing_milestone_id],
+    epics: %w[updated_by_id last_edited_by_id start_date_sourcing_milestone_id due_date_sourcing_milestone_id state_id],
     forked_project_links: %w[forked_from_project_id],
     geo_event_log: %w[hashed_storage_attachments_event_id],
     geo_job_artifact_deleted_events: %w[job_artifact_id],