adding string join nodes and a visitor to produce backwards compatible "join_sql"

10 files changed, 58 insertions, 6 deletions

diff --git a/lib/arel.rb b/lib/arel.rb
index b012c62179..2bfdef15d5 100644
--- a/lib/arel.rb
+++ b/lib/arel.rb
@@ -25,4 +25,5 @@ require 'arel/expression'
 ####
 
 require 'arel/visitors/to_sql'
+require 'arel/visitors/join_sql'
 require 'arel/visitors/dot'
diff --git a/lib/arel/nodes.rb b/lib/arel/nodes.rb
index f2332694a8..6dcd86867a 100644
--- a/lib/arel/nodes.rb
+++ b/lib/arel/nodes.rb
@@ -16,4 +16,5 @@ require 'arel/nodes/table_alias'
 require 'arel/nodes/join'
 require 'arel/nodes/inner_join'
 require 'arel/nodes/outer_join'
+require 'arel/nodes/string_join'
 require 'arel/nodes/on'
diff --git a/lib/arel/nodes/string_join.rb b/lib/arel/nodes/string_join.rb
new file mode 100644
index 0000000000..ea7912f92b
--- /dev/null
+++ b/lib/arel/nodes/string_join.rb
@@ -0,0 +1,11 @@
+module Arel
+  module Nodes
+    class StringJoin < Arel::Nodes::Join
+      undef :constraint
+
+      def initialize left, right
+        super(left, right, nil)
+      end
+    end
+  end
+end
diff --git a/lib/arel/select_manager.rb b/lib/arel/select_manager.rb
index d8e67cafab..736b122399 100644
--- a/lib/arel/select_manager.rb
+++ b/lib/arel/select_manager.rb
@@ -43,8 +43,10 @@ module Arel
     end
 
     def join_sql
-      viz = Visitors::ToSql.new @engine
-      @ctx.froms.grep(Nodes::Join).map { |x| viz.accept x }.join ', '
+      viz = Visitors::JoinSql.new @engine
+      Nodes::SqlLiteral.new(
+        @ctx.froms.grep(Nodes::Join).map { |x| viz.accept x }.join ', '
+      )
     end
 
     def joins manager
diff --git a/lib/arel/table.rb b/lib/arel/table.rb
index 02ece7ff07..b3a1a105d8 100644
--- a/lib/arel/table.rb
+++ b/lib/arel/table.rb
@@ -27,7 +27,14 @@ module Arel
     end
 
     def join relation
-      SelectManager.new(@engine).from(Nodes::InnerJoin.new(self, relation, nil))
+      sm = SelectManager.new(@engine)
+      case relation
+      when String, Nodes::SqlLiteral
+        raise if relation.blank?
+        sm.from Nodes::StringJoin.new(self, relation)
+      else
+        sm.from Nodes::InnerJoin.new(self, relation, nil)
+      end
     end
 
     def where condition
diff --git a/lib/arel/version.rb b/lib/arel/version.rb
index ba9cca430a..2c47fd2fe0 100644
--- a/lib/arel/version.rb
+++ b/lib/arel/version.rb
@@ -1,3 +1,3 @@
 module Arel
-  VERSION = '0.4.1.beta.1'
+  VERSION = '1.0.0.beta.1'
 end
diff --git a/lib/arel/visitors/dot.rb b/lib/arel/visitors/dot.rb
index ec2db0814f..277573f7fe 100644
--- a/lib/arel/visitors/dot.rb
+++ b/lib/arel/visitors/dot.rb
@@ -28,6 +28,11 @@ module Arel
       end
 
       private
+      def visit_Arel_Nodes_StringJoin o
+        visit_edge o, "left"
+        visit_edge o, "right"
+      end
+
       def visit_Arel_Nodes_InsertStatement o
         visit_edge o, "relation"
         visit_edge o, "columns"
diff --git a/lib/arel/visitors/join_sql.rb b/lib/arel/visitors/join_sql.rb
new file mode 100644
index 0000000000..95b27b4476
--- /dev/null
+++ b/lib/arel/visitors/join_sql.rb
@@ -0,0 +1,21 @@
+module Arel
+  module Visitors
+    ###
+    # This class produces SQL for JOIN clauses but omits the "single-source"
+    # part of the Join grammar:
+    #
+    #   http://www.sqlite.org/syntaxdiagrams.html#join-source
+    #
+    # This visitor is used in SelectManager#join_sql and is for backwards
+    # compatibility with Arel V1.0
+    class JoinSql < Arel::Visitors::ToSql
+      def visit_Arel_Nodes_OuterJoin o
+        "OUTER JOIN #{visit o.right} #{visit o.constraint}"
+      end
+
+      def visit_Arel_Nodes_InnerJoin o
+        "INNER JOIN #{visit o.right} #{visit o.constraint if o.constraint}"
+      end
+    end
+  end
+end
diff --git a/lib/arel/visitors/to_sql.rb b/lib/arel/visitors/to_sql.rb
index a0c8f67e13..a798d888d3 100644
--- a/lib/arel/visitors/to_sql.rb
+++ b/lib/arel/visitors/to_sql.rb
@@ -66,6 +66,10 @@ module Arel
         "#{visit o.relation} #{quote_table_name o.name}"
       end
 
+      def visit_Arel_Nodes_StringJoin o
+        "#{visit o.left} #{visit o.right}"
+      end
+
       def visit_Arel_Nodes_OuterJoin o
         "#{visit o.left} OUTER JOIN #{visit o.right} #{visit o.constraint}"
       end
diff --git a/spec/arel/select_manager_spec.rb b/spec/arel/select_manager_spec.rb
index 0120650a9f..380e381756 100644
--- a/spec/arel/select_manager_spec.rb
+++ b/spec/arel/select_manager_spec.rb
@@ -63,7 +63,7 @@ module Arel
         manager = Arel::SelectManager.new Table.engine
         manager.from Nodes::InnerJoin.new(table, aliaz, table[:id].eq(aliaz[:id]))
         manager.join_sql.should be_like %{
-          "users" INNER JOIN "users" "users_2" "users"."id" = "users_2"."id"
+          INNER JOIN "users" "users_2" "users"."id" = "users_2"."id"
         }
         check manager.joins(manager).should == manager.join_sql
       end
@@ -74,7 +74,7 @@ module Arel
         manager = Arel::SelectManager.new Table.engine
         manager.from Nodes::OuterJoin.new(table, aliaz, table[:id].eq(aliaz[:id]))
         manager.join_sql.should be_like %{
-          "users" OUTER JOIN "users" "users_2" "users"."id" = "users_2"."id"
+          OUTER JOIN "users" "users_2" "users"."id" = "users_2"."id"
         }
         check manager.joins(manager).should == manager.join_sql
       end