I have the following query to get a product ID, product name, price, description and ingredients from multiple tables.

```
SELECT TP.intProductID AS ProductID, TP.strName AS Name, TPP.decPrice AS Price,
TD.strDescription AS Description, GROUP_CONCAT( TRH.strName     SEPARATOR ', ' ) AS Ingredients 
FROM TProducts TP JOIN

     TProductsPrices TPP 
     on TP.intProductID=TPP.intProductID JOIN

     TProductsDescriptions TPD 
     on TP.intProductID=TPD.intProductID JOIN

     TDescriptions TD
     on TPD.intDescriptionID=TD.intDescriptionID JOIN

     TProductsIngredients TPI
     on TPD.intProductID=TPI.intProductID JOIN

     TRawHerbs TRH
     on TPI.intIngredientID=TRH.intRawHerbID

GROUP BY TPD.intProductID;

```

The query finds all the product info the way it should, but I want to be able to include products in my results that do not have a description in the description table (and maybe return null or an empty string instead). How can I do such a thing?