Modeling a graph of different node types and edge types using SQL Graph
How do I reconstruct the graph for this particular project?


To send data from SQL Server to the client, you use TDS, which means one result set per table "shape", or use JSON/XML encoded in a unicode string.

So yes, if you needed all the details for each node type, you would have one query per node type.  You can join the different tables together into fewer queries (as in EF Eager Loading), but that doesn't really improve the efficiency.