# Cassandrex
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[](http://inch-ci.org/github/vintikzzz/cassandrex)
[](https://ebertapp.io/github/vintikzzz/cassandrex)
Cassandra driver for Elixir on top of [cqerl][1]
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
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.
[1]: https://github.com/matehat/cqerl/
