mysql will lock for update

History.txt

@@ -1,3 +1,9 @@
+== 2.0.5 (unreleased)
+
+* Bug fixes
+
+  * #lock will lock SELECT statements "FOR UPDATE" on mysql
+
 == 2.0.4
 
 * Bug fixes

lib/arel/visitors/mysql.rb

@@ -2,6 +2,10 @@ module Arel
   module Visitors
     class MySQL < Arel::Visitors::ToSql
       private
+      def visit_Arel_Nodes_Lock o
+        "FOR UPDATE"
+      end
+
       ###
       # :'(
       # http://dev.mysql.com/doc/refman/5.0/en/select.html#id3482214

test/visitors/test_mysql.rb

@@ -22,6 +22,13 @@ module Visitors
         sql = @visitor.accept(stmt)
         sql.must_be_like "SELECT FROM DUAL"
       end
+
+      it 'uses FOR UPDATE when locking' do
+        stmt = Nodes::SelectStatement.new
+        stmt.lock = Nodes::Lock.new
+        sql = @visitor.accept(stmt)
+        sql.must_be_like "SELECT FROM DUAL FOR UPDATE"
+      end
     end
   end
 end