Fixed linked server compatability for SELECT queries.

Author: Jippe Holwerda

lib/arel/visitors/sqlserver.rb

@@ -13,6 +13,14 @@ class SQLServer < Arel::Visitors::ToSql
 
       # SQLServer ToSql/Visitor (Overides)
 
+      def visit_Arel_Attributes_Attribute o, collector
+        join_name = o.relation.table_alias ||
+          ActiveRecord::ConnectionAdapters::SQLServer::Utils.extract_identifiers(
+            o.relation.name
+          ).object_quoted
+        collector << "#{quote_table_name join_name}.#{quote_column_name o.name}"
+      end
+
       def visit_Arel_Nodes_BindParam o, collector
         collector.add_bind(o) { |i| "@#{i-1}" }
       end

test/cases/fully_qualified_identifier_test_sqlserver.rb

@@ -0,0 +1,58 @@
+require 'cases/helper_sqlserver'
+
+class FullyQualifiedIdentifierTestSQLServer < ActiveRecord::TestCase
+  it 'should use fully qualified table name in select from clause' do
+    table = Arel::Table.new("[my.server].db.schema.table")
+    expected_sql = "SELECT * FROM [my.server].[db].[schema].[table]"
+    assert_equal expected_sql, table.project(Arel.star).to_sql
+  end
+
+  it 'should not use fully qualified table name in select projections' do
+    table = Arel::Table.new("[my.server].db.schema.table")
+    expected_sql = "SELECT [table].[name] FROM [my.server].[db].[schema].[table]"
+    assert_equal expected_sql, table.project(table[:name]).to_sql
+  end
+
+  it 'should not use fully qualified table name in where clause' do
+    table = Arel::Table.new("[my.server].db.schema.table")
+    expected_sql = "SELECT * FROM [my.server].[db].[schema].[table] WHERE [table].[id] = 42"
+    assert_equal expected_sql, table.project(Arel.star).where(table[:id].eq(42)).to_sql
+  end
+
+  it 'should not use fully qualified table name in order clause' do
+    table = Arel::Table.new("[my.server].db.schema.table")
+    expected_sql = "SELECT * FROM [my.server].[db].[schema].[table]  ORDER BY [table].[name]"
+    assert_equal expected_sql, table.project(Arel.star).order(table[:name]).to_sql
+  end
+
+  it 'should use table name in select projections' do
+    table = Arel::Table.new(:table)
+    expected_sql = "SELECT [table].[name] FROM [table]"
+    assert_equal expected_sql, table.project(table[:name]).to_sql
+  end
+
+  it 'should use fully qualified table name in insert statement' do
+    manager = Arel::InsertManager.new(Arel::Table.engine)
+    manager.into Arel::Table.new("[my.server].db.schema.table")
+    manager.values = manager.create_values [Arel.sql('*')], %w{ a }
+    expected_sql = "INSERT INTO [my.server].[db].[schema].[table] VALUES (*)"
+    assert_equal expected_sql, manager.to_sql
+  end
+
+  it 'should use fully qualified table name in update statement' do
+    table = Arel::Table.new("[my.server].db.schema.table")
+    manager = Arel::UpdateManager.new(Arel::Table.engine)
+    manager.table(table).where(table[:id].eq(42))
+    manager.set([[table[:name], "Bob"]])
+    expected_sql = "UPDATE [my.server].[db].[schema].[table] SET [name] = N'Bob' WHERE [table].[id] = 42"
+    assert_equal expected_sql, manager.to_sql
+  end
+
+  it 'should use fully qualified table name in delete statement' do
+    table = Arel::Table.new("[my.server].db.schema.table")
+    manager = Arel::DeleteManager.new(Arel::Table.engine)
+    manager.from(table).where(table[:id].eq(42))
+    expected_sql = "DELETE FROM [my.server].[db].[schema].[table] WHERE [table].[id] = 42"
+    assert_equal expected_sql, manager.to_sql
+  end
+end