polyclay-cassandra-cql

cassandra persistence adapter for polyclay, the schema-enforcing document mapper

polyclay-cassandra-cql

A cassandra persistence adapter for Polyclay.

This module relies on node-cassandra-cql for its cassandra driver.

npm install polyclay-cassandra polyclay

Polyclay is a peer dependency of this module.

A quick example until more documentation is written:

var polyclay = require('polyclay'),
    CassandraAdapter = require('polyclay-cassandra'),
    cassandra = require('node-cassandra-cql')
    ;
 
 
var testKSName = 'polyclay_unit_tests';
var modelDefinition =
{
    properties:
    {
        key:           'string',
        name:          'string',
        created:       'date',
        foozles:       'array',
        snozzers:      'hash',
        is_valid:      'boolean',
        count:         'number',
        floating:      'number',
        map:            'string',
    },
    required:   [ 'name', 'is_valid', 'required_prop'],
    singular:   'model',
    plural:     'models'
};
 
Model = polyclay.Model.buildClass(modelDefinition);
polyclay.persist(Model);
 
var client = new cassandra.Client({
    hosts:    ['localhost'],
    port:     9042
});
 
var options =
{
    client: client,
    keyspace: 'polyclay_unit_tests',
    consistency: cassandra.types.consistencies.quorum
};
 
Model.setStorage(options, CassandraAdapter);

The keyspace is available at obj.adapter.keyspace and the model column family at obj.adapter.columnFamily. adapter.provision() creates keyspaces and column families if necessary. It is safe to call provision more than once; it will avoid trying to create the tables if they already exist.

Attachments are no longer supported by the cassandra adapter.

The adapter adds several cassandra-specific types to the core javascript type list. The polyclay model definition names are in the left column. Cassandra types are in the right. No attempt has been made to implement map types with anything other than string keys.

| Polyclay type   | Cassandra type
| ==============: | :=============
| string          | text
| number          | double
| boolean         | boolean
| date            | timestamp
| uuid            | uuid
| timeuuid        | timeuuid
| set:string      | set<text>
| set:number      | set<double>
| set:date        | set<timestamp>
| set:uuid        | set<uuid>
| set:timeuuid    | set<timeuuid>
| list:string     | list<text>
| list:number     | list<double>
| list:date       | list<timestamp>
| list:uuid       | list<uuid>
| list:timeuuid   | list<timeuuid>
| map:string      | map<text, text>
| map:boolean     | map<text, boolean>
| map:number      | map<text, double>
| map:date        | map<text, timestamp>
| map:uuid        | map<text, uuid>
| map:timeuuid    | map<text, timeuuid>
| array           | text (json-stringified)
| hash            | text (json-stringified)
| reference       | text (json-stringified)

TBD