Added support for RETURNING primary key when available, only for

PostgreSQL.

5 files changed, 23 insertions, 3 deletions

diff --git a/lib/arel/engines/sql/compilers/postgresql_compiler.rb b/lib/arel/engines/sql/compilers/postgresql_compiler.rb
index 4122bc730e..1f6e74d57a 100644
--- a/lib/arel/engines/sql/compilers/postgresql_compiler.rb
+++ b/lib/arel/engines/sql/compilers/postgresql_compiler.rb
@@ -33,6 +33,10 @@ module Arel
         order = orders.join(', ').split(/,/).map { |s| s.strip }.reject(&:blank?)
         order = order.zip((0...order.size).to_a).map { |s,i| "id_list.alias_#{i} #{'DESC' if s =~ /\bdesc$/i}" }.join(', ')
       end
+
+      def supports_insert_with_returning?
+        engine.postgresql_version >= 80200
+      end
     end
   end
 end
diff --git a/lib/arel/engines/sql/engine.rb b/lib/arel/engines/sql/engine.rb
index 82915fe890..79011a3db5 100644
--- a/lib/arel/engines/sql/engine.rb
+++ b/lib/arel/engines/sql/engine.rb
@@ -20,7 +20,7 @@ module Arel
 
       module CRUD
         def create(relation)
-          connection.insert(relation.to_sql, nil, relation.primary_key)
+          connection.execute(relation.to_sql)
         end
 
         def read(relation)
diff --git a/lib/arel/engines/sql/relations/compiler.rb b/lib/arel/engines/sql/relations/compiler.rb
index 4bc169096a..185f1a5c87 100644
--- a/lib/arel/engines/sql/relations/compiler.rb
+++ b/lib/arel/engines/sql/relations/compiler.rb
@@ -26,6 +26,10 @@ module Arel
         "WHERE #{quoted_primary_key} IN (SELECT #{quoted_primary_key} FROM #{engine.connection.quote_table_name table.name} #{conditions})"
       end
 
+      def supports_insert_with_returning?
+        false
+      end
+
     protected
       def method_missing(method, *args, &block)
         relation.send(method, *args, &block)
diff --git a/lib/arel/engines/sql/relations/writes.rb b/lib/arel/engines/sql/relations/writes.rb
index 30b36ddda8..00cd61cdde 100644
--- a/lib/arel/engines/sql/relations/writes.rb
+++ b/lib/arel/engines/sql/relations/writes.rb
@@ -32,7 +32,8 @@ module Arel
       build_query \
         "INSERT",
         "INTO #{table_sql}",
-        insertion_attributes_values_sql
+        insertion_attributes_values_sql,
+        ("RETURNING #{engine.quote_column_name(primary_key)}" if compiler.supports_insert_with_returning?)
     end
   end
 
diff --git a/spec/arel/engines/sql/unit/relations/insert_spec.rb b/spec/arel/engines/sql/unit/relations/insert_spec.rb
index 1884e32a3d..69c5bb052c 100644
--- a/spec/arel/engines/sql/unit/relations/insert_spec.rb
+++ b/spec/arel/engines/sql/unit/relations/insert_spec.rb
@@ -43,6 +43,7 @@ module Arel
             INSERT
             INTO "users"
             ("id", "name") VALUES (1, E'nick')
+            RETURNING "id"
           })
         end
       end
@@ -74,6 +75,7 @@ module Arel
               INSERT
               INTO "users"
               ("name") VALUES (E'nick')
+              RETURNING "id"
             })
           end
         end
@@ -93,11 +95,20 @@ module Arel
             })
           end
 
-          adapter_is_not :mysql do
+          adapter_is :sqlite3 do
+            @insertion.to_sql.should be_like(%Q{
+              INSERT
+              INTO "users"
+              ("id") VALUES (1)
+            })
+          end
+
+          adapter_is :postgresql do
             @insertion.to_sql.should be_like(%Q{
               INSERT
               INTO "users"
               ("id") VALUES (1)
+              RETURNING "id"
             })
           end
         end