What is the SPARQL query to check if a graph exists and return a message?

Question

I want to check if the graph exists in my Fuseki server and if it does, it should return a message like

The graph exists

Answer 1

You can do this with an ASK query. For example, to check that a named graph http://example.org/graph1 exists, you can do this:

ASK WHERE { GRAPH <http://example.org/graph1> { ?s ?p ?o } }

It will return true if it exists, false otherwise.