Cassandrex

Cassandra driver for Elixir on top of cqerl

Documentation: http://hexdocs.pm/cassandrex/

Features

• Encoding and decoding Cassandra data types to Elixir (with UDT support)
• Batches
• Paging (streaming)

Data type conversion rules

Cassandra       Elixir
---------       ------
ascii           string
bigint          integer
blob            binary
boolean         boolean
counter         integer
decimal         (not supported by cqerl)
double          float
float           float
inet            (not supported by cqerl)
int             integer
list            list
map             map
set             list
text            string
timestamp       integer
uuid            binary
timeuuid        binary
varchar         string
varint          integer
UDT             keyword list

Example

iex> alias Cassandrex, as: C
Cassandrex
iex> C.add_nodes(["127.0.0.1:9042"])
:ok
iex> {:ok, c} = C.get_client()
{:ok, {#PID<0.1031.0>, #Reference<0.0.1.2590>}}
iex> C.query(c, "CREATE KEYSPACE my_keyspace WITH REPLICATION = { 'class' : 'SimpleStrategy', 'replication_factor' : 1 }")
{:ok,
 %Cassandrex.Result{columns: [], command: :create, connection_id: nil,
  cqerl: {:cql_schema_changed, :created, :keyspace, "my_keyspace", :undefined,
   :undefined}, last_insert_id: nil, num_rows: 0, rows: [], spec: nil}}
iex> C.query(c, "USE my_keyspace")
{:ok,
 %Cassandrex.Result{columns: [], command: :use, connection_id: nil,
  cqerl: {:set_keyspace, "my_keyspace"}, last_insert_id: nil, num_rows: 0,
  rows: [], spec: nil}}
iex> C.query(c, "CREATE TABLE IF NOT EXISTS animals (name text PRIMARY KEY, legs tinyint, friendly boolean)")
{:ok,
 %Cassandrex.Result{columns: [], command: :create, connection_id: nil,
  cqerl: {:cql_schema_changed, :created, :table, "my_keyspace", "animals",
   :undefined}, last_insert_id: nil, num_rows: 0, rows: [], spec: nil}}
iex> statement = "INSERT INTO animals (name, legs, friendly) values (?, ?, ?)"
"INSERT INTO animals (name, legs, friendly) values (?, ?, ?)"
iex> C.query(c, statement, [name: "cat", legs: 4, friendly: false])
{:ok,
 %Cassandrex.Result{columns: [], command: :insert, connection_id: nil,
  cqerl: :void, last_insert_id: nil, num_rows: 0, rows: [], spec: nil}}
iex> C.query(c, statement, [name: "dog", legs: 4, friendly: true])
{:ok,
 %Cassandrex.Result{columns: [], command: :insert, connection_id: nil,
  cqerl: :void, last_insert_id: nil, num_rows: 0, rows: [], spec: nil}}
iex> C.query(c, "SELECT name, legs, friendly FROM #{table}")
{:ok,
 %Cassandrex.Result{columns: [:name, :legs, :friendly], command: :select,
  connection_id: nil,
  cqerl: {:cql_result,
   [{:cqerl_result_column_spec, "my_keyspace", "animals", :name, :varchar},
    {:cqerl_result_column_spec, "my_keyspace", "animals", :legs, :tinyint},
    {:cqerl_result_column_spec, "my_keyspace", "animals", :friendly, :boolean}],
   [[<<0, 0, 0, 3, 99, 97, 116>>, <<0, 0, 0, 1, 4>>, <<0, 0, 0, 1, 0>>],
    [<<0, 0, 0, 3, 100, 111, 103>>, <<0, 0, 0, 1, 4>>, <<0, 0, 0, 1, 1>>]],
   {:cql_query, "SELECT name, legs, friendly FROM animals", [], :undefined,
    false, 100, :undefined, 1, :undefined, :undefined},
   {#PID<0.1031.0>, #Reference<0.0.1.2597>}}, last_insert_id: nil, num_rows: 2,
  rows: [["cat", 4, false], ["dog", 4, true]],
  spec: [name: :varchar, legs: :tinyint, friendly: :boolean]}}

Installation

1. Add cassandrex and cqerl to your list of dependencies in mix.exs:

```elixir
def deps do
  [{:cqerl, github: "matehat/cqerl", tag: "v1.0.2", only: :test},
  {:cassandrex, "~> 0.1.0"}]
end
```

2. Ensure cassandrex is started before your application:

```elixir
def application do
  [applications: [:cassandrex]]
end
```

Contributing

To contribute you need to compile Cassandrex from source and test it:

$ git clone https://github.com/vintikzzz/cassandrex.git
$ cd cassandrex
$ mix deps.get
$ mix espec

License

Copyright 2016 Pavel Tatarskiy

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.