this Database structure will not work with dynamic drop downs.
your database structure should be more like:
articles:
articleId - primary Key
articleName - text
sparetypes:
spareTypeID - primary Key
sapreTypeName - text
articlespares:
articlesparesID - primary key
articlesparesSpareTypeID - foregin key to sparetypes.spareTypeID
articlesparesarticleId - foregin key to articles.articleId