Querying DSE Graph vertices and edges with Spark SQL

Spark SQL can query DSE Graph vertex and edge tables.

spark-sql> CREATE DATABASE graph_example;
spark-sql> USE graph_example;
spark-sql> CREATE TABLE vertices USING com.datastax.bdp.graph.spark.sql.vertex OPTIONS (graph 'example');
spark-sql> CREATE TABLE edges USING com.datastax.bdp.graph.spark.sql.edge OPTIONS (graph 'example');

1. Start the Spark SQL shell.

   dse spark-sql

2. Register the vertex and edge tables for your graph using CREATE TABLE.

   CREATE DATABASE graph_gods;
   USE graph_gods;
   CREATE TABLE vertices USING com.datastax.bdp.graph.spark.sql.vertex OPTIONS (graph 'gods');
   CREATE TABLE edges USING com.datastax.bdp.graph.spark.sql.edge OPTIONS (graph 'gods');

3. Query the vertices and edges using SELECT statements.

   SELECT * FROM vertices where name = 'Zeus';

4. Join the vertices and edges in a query.

   Vertices are identified by id columns. Edges tables have src and dst columns that identify the from and to vertices, respectively. A join can be used to traverse the graph. For example to find all vertex ids that are reached by the out edges:

   SELECT edges.dst FROM vertices JOIN edges ON vertices.id = edges.src;