Don't disable referential integrity for the same table twice

Author: buehmann

lib/active_record/connection_adapters/sqlserver_adapter.rb

@@ -189,7 +189,7 @@ def reset!
 
       def tables_with_referential_integrity
         schemas_and_tables = select_rows <<-SQL.strip_heredoc
-          SELECT s.name, o.name
+          SELECT DISTINCT s.name, o.name
           FROM sys.foreign_keys i
           INNER JOIN sys.objects o ON i.parent_object_id = o.OBJECT_ID
           INNER JOIN sys.schemas s ON o.schema_id = s.schema_id

test/cases/adapter_test_sqlserver.rb

@@ -231,6 +231,11 @@ class AdapterTestSQLServer < ActiveRecord::TestCase
       end
     end
 
+    it 'not disable referential integrity for the same table twice' do
+      tables = SSTestHasPk.connection.tables_with_referential_integrity
+      assert_equal tables.size, tables.uniq.size
+    end
+
   end
 
   describe 'database statements' do

test/schema/sqlserver_specific_schema.rb

@@ -144,12 +144,20 @@
 
   # Constraints
 
-  create_table(:sst_has_fks, force: true) { |t| t.column(:fk_id, :bigint, null: false) }
+  create_table(:sst_has_fks, force: true) do |t|
+    t.column(:fk_id, :bigint, null: false)
+    t.column(:fk_id2, :bigint)
+  end
+
   create_table(:sst_has_pks, force: true) { }
   execute <<-ADDFKSQL
     ALTER TABLE sst_has_fks
     ADD CONSTRAINT FK__sst_has_fks_id
     FOREIGN KEY ([fk_id])
+    REFERENCES [sst_has_pks] ([id]),
+
+    CONSTRAINT FK__sst_has_fks_id2
+    FOREIGN KEY ([fk_id2])
     REFERENCES [sst_has_pks] ([id])
   ADDFKSQL