Merge commit 'rails/master'

Conflicts:
	activerecord/test/cases/adapter_test.rb

6 files changed, 74 insertions, 1 deletions

diff --git a/activerecord/lib/active_record/base.rb b/activerecord/lib/active_record/base.rb
index c7fc1fa124..b3ecd01348 100755
--- a/activerecord/lib/active_record/base.rb
+++ b/activerecord/lib/active_record/base.rb
@@ -67,6 +67,25 @@ module ActiveRecord #:nodoc:
   class StatementInvalid < ActiveRecordError
   end
 
+  # Parent class for all specific exceptions which wrap database driver exceptions
+  # provides access to the original exception also.
+  class WrappedDatabaseException < StatementInvalid
+    attr_reader :original_exception
+
+    def initialize(message, original_exception)
+      super(message)
+      @original_exception, = original_exception
+    end
+  end
+
+  # Raised when a record cannot be inserted because it would violate a uniqueness constraint.
+  class RecordNotUnique < WrappedDatabaseException
+  end
+
+  # Raised when a record cannot be inserted or updated because it references a non-existent record.
+  class InvalidForeignKey < WrappedDatabaseException
+  end
+
   # Raised when number of bind variables in statement given to <tt>:condition</tt> key (for example, when using +find+ method)
   # does not match number of expected variables.
   #
diff --git a/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb b/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
index 91b111ab55..c533d4cdb6 100755
--- a/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
@@ -211,9 +211,14 @@ module ActiveRecord
           @last_verification = 0
           message = "#{e.class.name}: #{e.message}: #{sql}"
           log_info(message, name, 0)
-          raise ActiveRecord::StatementInvalid, message
+          raise translate_exception(e, message)
         end
 
+      def translate_exception(e, message)
+        # override in derived class
+        ActiveRecord::StatementInvalid.new(message)
+      end
+
         def format_log_entry(message, dump = nil)
           if ActiveRecord::Base.colorize_logging
             if @@row_even
diff --git a/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb b/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
index cee93dcac2..9173c8bca3 100644
--- a/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
@@ -552,6 +552,19 @@ module ActiveRecord
         where_sql
       end
 
+      protected
+
+        def translate_exception(exception, message)
+          case exception.errno
+          when 1062
+            RecordNotUnique.new(message, exception)
+          when 1452
+            InvalidForeignKey.new(message, exception)
+          else
+            super
+          end
+        end
+
       private
         def connect
           encoding = @config[:encoding]
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
index 6b230787c3..fc8ca357e5 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
@@ -928,6 +928,17 @@ module ActiveRecord
             end
         end
 
+        def translate_exception(exception, message)
+          case exception.message
+          when /duplicate key value violates unique constraint/
+            RecordNotUnique.new(message, exception)
+          when /violates foreign key constraint/
+            InvalidForeignKey.new(message, exception)
+          else
+            super
+          end
+        end
+
       private
         # The internal PostgreSQL identifier of the money data type.
         MONEY_COLUMN_TYPE_OID = 790 #:nodoc:
diff --git a/activerecord/lib/active_record/connection_adapters/sqlite_adapter.rb b/activerecord/lib/active_record/connection_adapters/sqlite_adapter.rb
index b33c460a93..8cbe08cd77 100644
--- a/activerecord/lib/active_record/connection_adapters/sqlite_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/sqlite_adapter.rb
@@ -432,6 +432,16 @@ module ActiveRecord
             'INTEGER PRIMARY KEY NOT NULL'.freeze
           end
         end
+
+        def translate_exception(exception, message)
+          case exception.message
+          when /column(s)? .* (is|are) not unique/
+            RecordNotUnique.new(message, exception)
+          else
+            super
+          end
+        end
+
     end
 
     class SQLite2Adapter < SQLiteAdapter # :nodoc:
diff --git a/activerecord/test/cases/adapter_test.rb b/activerecord/test/cases/adapter_test.rb
index 544daf8f60..12808194f9 100644
--- a/activerecord/test/cases/adapter_test.rb
+++ b/activerecord/test/cases/adapter_test.rb
@@ -109,4 +109,19 @@ class AdapterTest < ActiveRecord::TestCase
       end
     end
   end
+
+  def test_uniqueness_violations_are_translated_to_specific_exception
+    @connection.execute "INSERT INTO subscribers(nick) VALUES('me')"
+    assert_raises(ActiveRecord::RecordNotUnique) do
+      @connection.execute "INSERT INTO subscribers(nick) VALUES('me')"
+    end
+  end
+
+  def test_foreign_key_violations_are_translated_to_specific_exception
+    unless @connection.adapter_name == 'SQLite'
+      assert_raises(ActiveRecord::InvalidForeignKey) do
+        @connection.execute "INSERT INTO fk_test_has_fk (fk_id) VALUES (0)"
+      end
+    end
+  end
 end