Add identity insert support for views. Cache #views so that identity #table_name_or_views_table_name will run quickly.

Author: metaskills

CHANGELOG

@@ -1,7 +1,11 @@
 
 *MASTER* ()
 
-* 
+* Add identity insert support for views. Cache #views so that identity #table_name_or_views_table_name 
+  will run quickly. [Ken Collins]
+
+* Add views support. ActiveRecord classes can use views. The connection now has a #views method and 
+  #table_exists? will not fall back to checking views too. [Ken Collins]
 
 
 *2.2.0* (November 21st, 2008)

lib/active_record/connection_adapters/sqlserver_adapter.rb

@@ -167,7 +167,7 @@ def type_limitable?(type)
       def initialize(connection, logger, connection_options=nil)
         super(connection, logger)
         @connection_options = connection_options
-        @sqlserver_columns_cache = {}
+        initialize_sqlserver_caches
         unless SUPPORTED_VERSIONS.include?(database_year)
           raise NotImplementedError, "Currently, only #{SUPPORTED_VERSIONS.to_sentence} are supported."
         end
@@ -447,7 +447,17 @@ def tables(name = nil)
       end
 
       def views(name = nil)
-        select_values "SELECT TABLE_NAME FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_TYPE = 'VIEW' AND TABLE_NAME NOT IN ('sysconstraints','syssegments')"
+        @sqlserver_views_cache ||= 
+          select_values "SELECT TABLE_NAME FROM INFORMATION_SCHEMA.VIEWS WHERE TABLE_NAME NOT IN ('sysconstraints','syssegments')"
+      end
+      
+      def view_information(table_name)
+        select_one "SELECT * FROM INFORMATION_SCHEMA.VIEWS WHERE TABLE_NAME = '#{table_name}'"
+      end
+      
+      def view_table_name(table_name)
+        view_info = view_information(table_name)
+        view_info ? get_table_name(view_info['VIEW_DEFINITION']) : table_name
       end
 
       def table_exists?(table_name)
@@ -741,6 +751,7 @@ def default_name(table_name, column_name)
       # IDENTITY INSERTS =========================================#
 
       def with_identity_insert_enabled(table_name, &block)
+        table_name = table_name_or_views_table_name(table_name)
         set_identity_insert(table_name, true)
         yield
       ensure
@@ -768,6 +779,11 @@ def identity_column(table_name)
         columns(table_name).detect(&:is_identity?)
       end
 
+      def table_name_or_views_table_name(table_name)
+        unquoted_table_name = unqualify_table_name(table_name)
+        views.include?(unquoted_table_name) ? view_table_name(unquoted_table_name) : table_name
+      end
+      
       # HELPER METHODS ===========================================#
 
       def insert_sql?(sql)
@@ -823,6 +839,12 @@ def sql_for_association_limiting?(sql)
       def remove_sqlserver_columns_cache_for(table_name)
         cache_key = unqualify_table_name(table_name)
         @sqlserver_columns_cache[cache_key] = nil
+        initialize_sqlserver_caches(false)
+      end
+      
+      def initialize_sqlserver_caches(reset_columns=true)
+        @sqlserver_columns_cache = {} if reset_columns
+        @sqlserver_views_cache = nil
       end
 
       def column_definitions(table_name)

lib/core_ext/active_record.rb

@@ -5,7 +5,7 @@ module SQLServerActiveRecordExtensions
       def self.included(klass)
         klass.extend ClassMethods
         class << klass
-          alias_method_chain :reset_column_information, :sqlserver_columns_cache_support
+          alias_method_chain :reset_column_information, :sqlserver_cache_support
           alias_method_chain :add_order!, :sqlserver_unique_checking
         end
       end
@@ -28,9 +28,9 @@ def coerced_sqlserver_time_columns
           read_inheritable_attribute(:coerced_sqlserver_time_columns) || []
         end
 
-        def reset_column_information_with_sqlserver_columns_cache_support
-          connection.instance_variable_set :@sqlserver_columns_cache, {}
-          reset_column_information_without_sqlserver_columns_cache_support
+        def reset_column_information_with_sqlserver_cache_support
+          connection.send(:initialize_sqlserver_caches)
+          reset_column_information_without_sqlserver_cache_support
         end
 
         private

test/cases/adapter_test_sqlserver.rb

@@ -369,7 +369,18 @@ def setup
           assert !@connection.views.include?(systable), "This systable #{systable} should not be in the views array."
         end
       end
-
+      
+      should 'allow the connection.view_information method to return meta data on the view' do
+        view_info = @connection.view_information('customers_view')
+        assert_equal('customers_view', view_info['TABLE_NAME'])
+        assert_match(/CREATE VIEW customers_view/, view_info['VIEW_DEFINITION'])
+      end
+      
+      should 'allow the connection.view_table_name method to return true table_name for the view' do
+        assert_equal 'customers', @connection.view_table_name('customers_view')
+        assert_equal 'topics', @connection.view_table_name('topics'), 'No view here, the same table name should come back.'
+      end
+      
     end
 
     context 'used by a class for table_name' do
@@ -392,6 +403,23 @@ def setup
 
     end
 
+    context 'doing identity inserts' do
+
+      setup do
+        @view_insert_sql = "INSERT INTO [customers_view] ([id],[name],[balance]) VALUES (420,'Microsoft',0)"
+      end
+      
+      should 'respond true/tablename to #query_requires_identity_insert?' do
+        assert_equal '[customers_view]', @connection.send(:query_requires_identity_insert?,@view_insert_sql)
+      end
+      
+      should 'be able to do an identity insert' do
+        assert_nothing_raised { @connection.execute(@view_insert_sql) }
+        assert CustomersView.find(420)
+      end
+
+    end
+    
   end