adding some backwards compatibility

2 files changed, 16 insertions, 0 deletions

diff --git a/lib/arel/select_manager.rb b/lib/arel/select_manager.rb
index c62101077a..0f70a461a3 100644
--- a/lib/arel/select_manager.rb
+++ b/lib/arel/select_manager.rb
@@ -50,6 +50,10 @@ module Arel
     end
 
     def from table
+      if String === table
+        return self if @ctx.froms.any? { |x| x.name.to_s == table }
+      end
+
       @ctx.froms << table
       self
     end
diff --git a/spec/arel/select_manager_spec.rb b/spec/arel/select_manager_spec.rb
index ba4a51eb56..86a4daee44 100644
--- a/spec/arel/select_manager_spec.rb
+++ b/spec/arel/select_manager_spec.rb
@@ -27,6 +27,18 @@ module Arel
 
   describe 'select manager' do
     describe 'backwards compatibility' do
+      describe 'from' do
+        it 'ignores strings when table of same name exists' do
+          table   = Table.new :users
+          manager = Arel::SelectManager.new Table.engine
+
+          manager.from table
+          manager.from 'users'
+          manager.project table['id']
+          manager.to_sql.should be_like 'SELECT "users"."id" FROM "users"'
+        end
+      end
+
       describe '#having' do
         it 'converts strings to SQLLiterals' do
           table   = Table.new :users