anchor.diff:  form_condition({Key, {ge, _Value}}) ->
     lists:flatten(["(", escape(Key), ">=?", ")"]);
   
  -form_condition({Key, undefined}) ->
  +form_condition({_Key, undefined}) ->
     "";
   
   form_condition({Key, _Value}) ->
  
positive.code:   Conditions = [{Key, V} || V <- Values],
    form_condition({'or', Conditions});
  
  form_condition({Key, {_, undefined}}) ->
    "";
  
  form_condition({Key, {le, _Value}}) ->
  
negative.code:     WhereFields
    ),
    Where = string:join(WFields, " AND "),
    {["DELETE FROM ", escape(TableName), " WHERE ", Where], WValues}.
  
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  %%% Private API.
  