Contentful and GraphQL with Gatsby

I am trying to create a graphQL query that will return me all the slugs for all the content Models I have in my account rather than just for one content model. For example I have a content model for cars and a content model for trucks, The content model for cars has 10 articles and the content model for trucks has 20 articles. Is it possible to return a graphQL contentful query that grabs all 30 articles?!

Thank you!