In Apache Spark 2.0.0, is it possible to fetch a query from an external database (rather than grab the whole table)?

Using pyspark:

from pyspark.sql import SparkSession

spark = SparkSession\
    .builder\
    .appName("spark play")\
    .getOrCreate()    

df = spark.read\
    .format("jdbc")\
    .option("url", "jdbc:mysql://localhost:port")\
    .option("dbtable", "schema.tablename")\
    .option("user", "username")\
    .option("password", "password")\
    .load()

Rather than fetch "schema.tablename", I would prefer to grab the result set of a query.

Same as in 1.x you can pass valid subquery as dbtable argument for example:

...
.option("dbtable", "(SELECT foo, bar FROM schema.tablename) AS tmp")
...