Add an #table_name method to Table and TableAlias, which always returns the actual table name, not the alias. Then fix ToSql#column_for to use this table name when checking whether the table exists (rather than before, where it was checking whether a table with the alias name exists, which was incorrect).

5 files changed, 21 insertions, 1 deletions

diff --git a/lib/arel/nodes/table_alias.rb b/lib/arel/nodes/table_alias.rb
index 4f4d5e29e9..1d3d36be0c 100644
--- a/lib/arel/nodes/table_alias.rb
+++ b/lib/arel/nodes/table_alias.rb
@@ -8,6 +8,10 @@ module Arel
       def [] name
         Attribute.new(self, name)
       end
+
+      def table_name
+        relation.name
+      end
     end
   end
 end
diff --git a/lib/arel/table.rb b/lib/arel/table.rb
index d1d1e40e11..2aff71b220 100644
--- a/lib/arel/table.rb
+++ b/lib/arel/table.rb
@@ -8,6 +8,9 @@ module Arel
 
     attr_accessor :name, :engine, :aliases, :table_alias
 
+    # TableAlias and Table both have a #table_name which is the name of the underlying table
+    alias :table_name :name
+
     def initialize name, engine = Table.engine
       @name    = name.to_s
       @engine  = engine
diff --git a/lib/arel/visitors/to_sql.rb b/lib/arel/visitors/to_sql.rb
index 70e10a5e0f..f76c1491ee 100644
--- a/lib/arel/visitors/to_sql.rb
+++ b/lib/arel/visitors/to_sql.rb
@@ -88,7 +88,7 @@ key on UpdateManager using UpdateManager#key=
 
       def column_for attr
         name    = attr.name.to_s
-        table   = attr.relation.name
+        table   = attr.relation.table_name
 
         return nil unless table_exists? table
 
diff --git a/test/test_table.rb b/test/test_table.rb
index 129d7ba736..1035540513 100644
--- a/test/test_table.rb
+++ b/test/test_table.rb
@@ -164,6 +164,10 @@ module Arel
       @relation.name.must_equal 'users'
     end
 
+    it "should have a table name" do
+      @relation.table_name.must_equal 'users'
+    end
+
     it "should have an engine" do
       @relation.engine.must_equal Table.engine
     end
diff --git a/test/visitors/test_to_sql.rb b/test/visitors/test_to_sql.rb
index c8ad40e242..2d5549ca43 100644
--- a/test/visitors/test_to_sql.rb
+++ b/test/visitors/test_to_sql.rb
@@ -259,6 +259,15 @@ module Arel
           }
         end
       end
+
+      describe 'TableAlias' do
+        it "should use the underlying table for checking columns" do
+          test = Table.new(:users).alias('zomgusers')[:id].eq '3'
+          @visitor.accept(test).must_be_like %{
+            "zomgusers"."id" = 3
+          }
+        end
+      end
     end
   end
 end