Enum data type in Cassandra

Question

I am trying to migrate my database from MySQL to Cassasndra. The problem I am facing is with one of the column type defined as Enum (enum('GP','NGP','PGP','PAGP')). Cassandra does not support Enum data types (it supports collections though). Is there a way to implement Enum data type in Cassandra, so that the value of a column should be restricted from a set of values? I am using Apache Cassandra version 2.0.7.

Answer 1

See datastax cassandra Object-mapping API,

http://docs.datastax.com/en/developer/java-driver/2.1/java-driver/reference/crudOperations.html

enum Gender { FEMALE, MALE };

// FEMALE will be persisted as 'FEMALE'
@Enumerated(EnumType.STRING)
private Gender gender;

// FEMALE will be persisted as 0, MALE as 1
@Enumerated(EnumType.ORDINAL)
private Gender gender

for cassandra 3.0

enum State {INIT, RUNNING, STOPPING, STOPPED}

cluster.getConfiguration().getCodecRegistry()
        .register(new EnumNameCodec<State>(State.class));

// schema: create table name_example(id int PRIMARY KEY, state text)
session.execute("insert into name_example (id, state) values (1, ?)", State.INIT);
// state is saved as 'INIT'

http://docs.datastax.com/en/developer/java-driver/3.1/manual/custom_codecs/extras/

Answer 2

As far I know and after reading the documentation about cql types, you can not use directly enum in cql statements (I check this for the java clients).

So the option you have is convert the Enum to String to include the field in a cql statement. BY this way all your application use the Enum but in the backend layer use the string representation for the enum.