CassAPI

Setup

As per best practices, we disable schema creation and handle that by hand with CQL commands, externally to the application.

USE <your_keyspace>;
CREATE TABLE taxa (
    id uuid PRIMARY KEY,
    description text,
    level text,
    name text,
    parent uuid
);
CREATE CUSTOM INDEX taxa_name_index ON taxa (name) USING 'StorageAttachedIndex' WITH OPTIONS = {'case_sensitive': true};
CREATE CUSTOM INDEX taxa_parent_index ON taxa (parent) USING 'StorageAttachedIndex';

CREATE TABLE species (
    parent uuid,
    name text,
    common_names frozen<map<text, text>>,
    description text,
    photo_url text,
    PRIMARY KEY (parent, name)
) WITH CLUSTERING ORDER BY (name ASC);
CREATE CUSTOM INDEX species_name_index ON species (name) USING 'StorageAttachedIndex' WITH OPTIONS = {'case_sensitive': true};

Notes

Template vs Operations

Class CassandraTemplate implements interface CassandraOperations.

The latter in turn has a getCqlOperations method returning a CqlOperations object: this has lower-level stuff.

Annotate table names, etc

Table names, primary/partition keys, column names: better to explicitly annotate everything in the domain class.

Repository and finding by non-key

Just adding the method signature in the repository interface will make Spring Data Cassandra fill it for you:

Optional<Taxon> findByName(String name);

What to execute with a CassandraTemplate

Both Query and SimpleStatement work fine:

SimpleStatement select1 = SimpleStatement.builder("SELECT * FROM taxon WHERE parent=?")
       .addPositionalValues(id)
       .build();

Query select2 = Query.query(Criteria.where("parent").is(id));

// those are both OK:
cassandraTemplate.select(select1, Taxon.class) [...];
cassandraTemplate.select(select2, Taxon.class) [...];

Interchangeability Astra/Cassandra

To switch from Astra to Cassandra, two things:

first, comment this Astra dependency in pom.xml:

<dependency>
  <groupId>com.datastax.astra</groupId>
  <artifactId>astra-spring-boot-starter</artifactId>
  <version>0.3.0</version>
</dependency>

second, adjust application.yaml to replace

astra:
  api:
    application-token: ...
    database-id: ...
    database-region: ...
  cql:
    enabled: true
    download-scb:
      enabled: true
    driver-config:
      basic:
        session-keyspace: ...

with

spring:
  data:
    cassandra:
      schema-action: NONE
      contactpoints: ...
      local-datacenter: datacenter1
      keyspace-name: ...

Also, of course, make sure your code does not use the Astra SDK Stargate-specific stuff (e.g. does not import/use [blabla].astra.AstraClient).