Improve migration for repository_row_connections [SCI-9908] (#6863)

app/helpers/database_helper.rb

@@ -60,26 +60,4 @@ module DatabaseHelper
       "AS t WHERE t.id = #{id};"
     ).getvalue(0, 0).to_i
   end
-
-  # Adds a check constraint to the table
-  def add_check_constraint(table, constraint_name, constraint)
-    ActiveRecord::Base.connection.execute(
-      "ALTER TABLE " \
-      "#{table} " \
-      "DROP CONSTRAINT IF EXISTS #{constraint_name}, " \
-      "ADD CONSTRAINT " \
-      "#{constraint_name} " \
-      "CHECK ( #{constraint} ) " \
-      "not valid;"
-    )
-  end
-
-  # Remove constraint from the table
-  def drop_constraint(table, constraint_name)
-    ActiveRecord::Base.connection.execute(
-      "ALTER TABLE " \
-      "#{table} " \
-      "DROP CONSTRAINT IF EXISTS #{constraint_name}; "
-    )
-  end
 end

db/migrate/20230922085412_add_repository_row_connections.rb

@@ -3,19 +3,24 @@
 class AddRepositoryRowConnections < ActiveRecord::Migration[7.0]
   def change
     create_table :repository_row_connections do |t|
-      t.references :parent, index: true, foreign_key: { to_table: :repository_rows }
-      t.references :child, index: true, foreign_key: { to_table: :repository_rows }
+      t.references :parent, index: true, foreign_key: { to_table: :repository_rows }, null: false
+      t.references :child, index: true, foreign_key: { to_table: :repository_rows }, null: false
       t.references :created_by, foreign_key: { to_table: :users }
       t.references :last_modified_by, foreign_key: { to_table: :users }
 
       t.timestamps
     end
 
-    add_index :repository_row_connections, %i(parent_id child_id), unique: true
-
     change_table :repository_rows, bulk: true do |t|
       t.integer :parent_connections_count
       t.integer :child_connections_count
     end
+
+    add_index :repository_row_connections,
+              'LEAST(parent_id, child_id), GREATEST(parent_id, child_id)',
+              name: 'index_repository_row_connections_on_connection_pair',
+              unique: true
+    add_check_constraint :repository_row_connections, 'parent_id != child_id',
+                         name: 'constraint_repository_row_connections_on_self_connection'
   end
 end

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[7.0].define(version: 2023_11_28_123835) do
+ActiveRecord::Schema[7.0].define(version: 2023_12_07_092907) do
   # These are extensions that must be enabled in order to support this database
   enable_extension "btree_gist"
   enable_extension "pg_trgm"
@@ -792,17 +792,18 @@ ActiveRecord::Schema[7.0].define(version: 2023_11_28_123835) do
   end
 
   create_table "repository_row_connections", force: :cascade do |t|
-    t.bigint "parent_id"
-    t.bigint "child_id"
+    t.bigint "parent_id", null: false
+    t.bigint "child_id", null: false
     t.bigint "created_by_id"
     t.bigint "last_modified_by_id"
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
+    t.index "LEAST(parent_id, child_id), GREATEST(parent_id, child_id)", name: "index_repository_row_connections_on_connection_pair", unique: true
     t.index ["child_id"], name: "index_repository_row_connections_on_child_id"
     t.index ["created_by_id"], name: "index_repository_row_connections_on_created_by_id"
     t.index ["last_modified_by_id"], name: "index_repository_row_connections_on_last_modified_by_id"
-    t.index ["parent_id", "child_id"], name: "index_repository_row_connections_on_parent_id_and_child_id", unique: true
     t.index ["parent_id"], name: "index_repository_row_connections_on_parent_id"
+    t.check_constraint "parent_id <> child_id", name: "constraint_repository_row_connections_on_self_connection"
   end
 
   create_table "repository_rows", force: :cascade do |t|

lib/tasks/sign_up_constraint.rake

@@ -2,8 +2,6 @@ namespace :sign_up_constraint do
   desc 'Adds email domain constraint to the users table. '\
         'E.g: scinote.net'
   task :email_domain, [:domain] => :environment do |_, args|
-    include DatabaseHelper
-
     if args.blank? || args[:domain].blank?
       puts 'Please add the email domain'
       return
@@ -12,19 +10,18 @@ namespace :sign_up_constraint do
     domain = args[:domain]
     domain = domain.strip.gsub(/\./, '\\.')
 
-    add_check_constraint(
-      'users',
-      'email_must_be_company_email',
-      "email ~* '^[A-Za-z0-9._%-+]+@#{domain}'"
+    ActiveRecord::Migration.add_check_constraint(
+      :users,
+      "email ~* '^[A-Za-z0-9._%-+]+@#{domain}'",
+      name: 'email_must_be_company_email',
+      validate: false
     )
     puts "Created the following domain constraint: #{args[:domain]}"
   end
 
   desc 'Remove email domain constraint from the users table.'
   task remove_domain: :environment do
-    include DatabaseHelper
-
-    drop_constraint('users', 'email_must_be_company_email')
+    ActiveRecord::Migration.remove_check_constraint :users, name: 'email_must_be_company_email'
     puts 'Email constraint has been removed'
   end
 end

spec/models/repository_row_connection_spec.rb

@@ -12,7 +12,6 @@ RSpec.describe RepositoryRowConnection, type: :model do
     it { should have_db_column(:child_id).of_type(:integer) }
     it { should have_db_column(:created_by_id).of_type(:integer) }
     it { should have_db_column(:last_modified_by_id).of_type(:integer) }
-    it { should have_db_index([:parent_id, :child_id]).unique(true) }
     it { should have_db_index(:parent_id) }
     it { should have_db_index(:child_id) }
     it { should have_db_index(:created_by_id) }