Perform the following steps to load data from Cassandra:

1. Create a keyspace named people in Cassandra using the CQL shell:

cqlsh> CREATE KEYSPACE people WITH replication = {'class': 'SimpleStrategy', 'replication_factor': 1 };

2. Create a column family (from CQL 3.0 onwards, it can also be called a table) person :

cqlsh> use people:
cqlsh> create table person(id int primary key,first_name varchar,last_name varchar,age int);

3. Insert a few records in the column family:

cqlsh> insert into person(id, first_name, last_name, age) values(1,'Barack','Obama',55);
cqlsh> insert into person(id, first_name, last_name, age) values(2,'Joe','Smith',14);                          cqlsh> insert into person(id, first_name, last_name, age) values(3,'Billy','Kid',18);

4. Now start the Spark shell with Cassandra connector dependency added:

$ spark-shell --packages datastax:spark-cassandra-connector:2.0.0-M2-s_2.11 --conf spark.cassandra.connection.host=localhost 

5. Load the person table as a DataFrame:

scala> val person = spark.read.format("org.apache.spark.sql.cassandra").options(Map("keyspace" ->"people", "table" -> "person")).load

6. Print the schema:

scala> person.printSchema
root
 |-- name: string (nullable = true)
 |-- age: integer (nullable = true)

7. Count the number of records in the DataFrame:

scala> person.count

8. Print persons DataFrame:

scala> person.show
+---+---+----------+---------+
| id|age|first_name|last_name|
+---+---+----------+---------+
| 1| 55| Barack| Obama|
| 2| 14| Joe| Smith|
| 3| 18| Billy| Kid|
+---+---+----------+---------+

9. Retrieve the first row:

scala> val firstRow = person.first

10. Create a Person case class:

scala> case class Person( first_name:String, last_name:String, age:Int)

11. Create a temporary view out of person DataFrame:

scala> person.createOrReplaceTempView("persons")

12. Create a DataFrame of teenagers:

scala> val teens = spark.sql("select * from persons where age > 12 and age < 20")

13. Print the teens DataFrame:

scala> teens.show

14. Convert it into dataset:

scala> val teensDS = teens.as[Person]