Remove not null constraint from events table

Fix different file

Add cr remarks

Fix

changelogs/unreleased/fix_deleting_user_psql_error_on_events_table_v2.yml

+---
+title: Remove not null constraint from events tables
+merge_request: 34190
+author:
+type: fixed

db/migrate/20200609142506_remove_not_null_constraint_from_weight_events_table.rb

+# frozen_string_literal: true
+
+class RemoveNotNullConstraintFromWeightEventsTable < ActiveRecord::Migration[6.0]
+  DOWNTIME = false
+
+  def change
+    change_column_null :resource_weight_events, :user_id, true
+  end
+end

db/migrate/20200609142507_remove_not_null_constraint_from_milestone_events_table.rb

+# frozen_string_literal: true
+
+class RemoveNotNullConstraintFromMilestoneEventsTable < ActiveRecord::Migration[6.0]
+  DOWNTIME = false
+
+  def change
+    change_column_null :resource_milestone_events, :user_id, true
+  end
+end

db/migrate/20200609142508_remove_not_null_constraint_from_state_events_table.rb

+# frozen_string_literal: true
+
+class RemoveNotNullConstraintFromStateEventsTable < ActiveRecord::Migration[6.0]
+  DOWNTIME = false
+
+  def change
+    change_column_null :resource_state_events, :user_id, true
+  end
+end

db/structure.sql

@@ -5955,7 +5955,7 @@ ALTER SEQUENCE public.resource_label_events_id_seq OWNED BY public.resource_labe
 
 CREATE TABLE public.resource_milestone_events (
     id bigint NOT NULL,
-    user_id bigint NOT NULL,
+    user_id bigint,
     issue_id bigint,
     merge_request_id bigint,
     milestone_id bigint,
@@ -5975,7 +5975,7 @@ ALTER SEQUENCE public.resource_milestone_events_id_seq OWNED BY public.resource_
 
 CREATE TABLE public.resource_state_events (
     id bigint NOT NULL,
-    user_id bigint NOT NULL,
+    user_id bigint,
     issue_id bigint,
     merge_request_id bigint,
     created_at timestamp with time zone NOT NULL,
@@ -5995,7 +5995,7 @@ ALTER SEQUENCE public.resource_state_events_id_seq OWNED BY public.resource_stat
 
 CREATE TABLE public.resource_weight_events (
     id bigint NOT NULL,
-    user_id bigint NOT NULL,
+    user_id bigint,
     issue_id bigint NOT NULL,
     weight integer,
     created_at timestamp with time zone NOT NULL
@@ -13967,6 +13967,9 @@ COPY "schema_migrations" (version) FROM STDIN;
 20200608075553
 20200608214008
 20200609002841
+20200609142506
+20200609142507
+20200609142508
 20200609212701
 \.