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https://github.com/sagastume/boltx

Neo4j driver for Elixir
https://github.com/sagastume/boltx

bolt bolt-protocol database-driver driver elixir graphdb neo4j neo4j-driver

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Neo4j driver for Elixir

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README

          

# Boltx

`Boltx` is an Elixir driver for [Neo4j](https://neo4j.com/developer/graph-database/)/Bolt Protocol.

- Supports Neo4j versions: 3.0.x/3.1.x/3.2.x/3.4.x/3.5.x/4.x/5.9 -5.13.0
- Supports Bolt version: 1.0/2.0/3.0/4.x/5.0/5.1/5.2/5.3/5.4
- Supports transactions, prepared queries, streaming, pooling and more via DBConnection
- Automatic decoding and encoding of Elixir values

Documentation: [https://hexdocs.pm/boltx](https://hexdocs.pm/boltx)

## Features

| Feature | Implemented |
| --------------------- | ------------ |
| Querys | YES |
| Transactions | YES |
| Stream capabilities | NO |
| Routing | NO |

## Usage

Add :boltx to your dependencies:

```elixir
def deps() do
[
{:boltx, "~> 0.0.6"}
]
end
```

Using the latest version.

```elixir

opts = [
hostname: "127.0.0.1",
auth: [username: "neo4j", password: ""],
user_agent: "boltxTest/1",
pool_size: 15,
max_overflow: 3,
prefix: :default
]

iex> {:ok, conn} = Boltx.start_link(opts)
{:ok, #PID<0.237.0>}

iex> Boltx.query!(conn, "return 1 as n") |> Boltx.Response.first()
%{"n" => 1}

# Commit is performed automatically if everythings went fine
Boltx.transaction(conn, fn conn ->
result = Boltx.query!(conn, "CREATE (m:Movie {title: "Matrix"}) RETURN m")
end)

```

### Set it up in an app

Add the configuration to the corresponding files for each environment or to your config/config.ex.
> #### Name of process
>
> The process name must be defined in your configuration

```elixir
import Config

config :boltx, Bolt,
uri: "bolt://localhost:7687",
auth: [username: "neo4j", password: "password"],
user_agent: "boltxTest/1",
pool_size: 15,
max_overflow: 3,
prefix: :default,
name: Bolt
```

Add Boltx to the application's main monitoring tree and let OTP manage it.

```elixir
# lib/n4_d/application.ex

defmodule N4D.Application do
@moduledoc false

use Application

def start(_type, _args) do
children = [
%{
id: Boltx,
start: {Boltx, :start_link, [Application.get_env(:boltx, Bolt)] },
}
]

opts = [strategy: :one_for_one, name: N4D.Supervisor]
Supervisor.start_link(children, opts)
end
end
```
Or

```elixir
children = [
{Boltx, Application.get_env(:boltx, Bolt)}
]
```
Now you can run query with the name you set

```elixir
iex> Boltx.query!(Bolt, "return 1 as n") |> Boltx.Response.first()
%{"n" => 1}
```

### URI schemes

By default the scheme is `bolt+s`

| URI | Description | TLSOptions |
|------------|--------------------------------------------|-------------------------|
| neo4j | Unsecured | [] |
| neo4j+s | Secured with full certificate | [verify: :verify_none] |
| neo4j+ssc | Secured with self-signed certificate | [verify: :verify_peer] |
| bolt | Unsecured | [] |
| bolt+s | Secured with full certificate | [verify: :verify_none] |
| bolt+ssc | Secured with self-signed certificate | [verify: :verify_peer] |

## Contributing

### Getting Started

Neo4j uses the Bolt protocol for communication and query execution. You can find the official documentation for Bolt here: [Bolt Documentation](https://neo4j.com/docs/bolt/current).

It is crucial to grasp various concepts before getting started, with the most important ones being:

- [PackStream](https://neo4j.com/docs/bolt/current/packstream/): The syntax layer for the Bolt messaging protocol.
- [Bolt Protocol](https://neo4j.com/docs/bolt/current/bolt/): The application protocol for database queries via a database query language.
- Bolt Protocol handshake specification
- Bolt Protocol message specification
- Structure Semantics

It is advisable to use the specific terminology from the official documentation and official drivers to ensure consistency with this implementation.

### Test

As certain versions of Bolt may be compatible with specific functionalities while others can undergo significant changes, tags are employed to facilitate version-specific testing. Some of these tags include:

- `:core` (Included in all executions).
- `:bolt_version_{{specific version}}` (Tag to run the test on a specific version, for example, for 5.2: `:bolt_version_5_2`, for version 1: `:bolt_version_1_0)`.
- `bolt_{major version}_x` (Tag to run on all minor versions of a major version, for example, for 5: `:bolt_5_x`, for all minor versions of 4:: `:bolt_4_x`).
- `:last_version` (Tag to run the test only on the latest version).

By default, all tags are disabled except the `:core` tag. To enable the tags, it is necessary to configure the following environment variables:

- `BOLT_VERSIONS`: This variable is used for Bolt version configuration but is also useful for testing. You can specify a version, for example, BOLT_VERSIONS="1.0".
- `BOLT_TCP_PORT`: You can configure the port with the environment variable (BOLT_TCP_PORT=7688).

#### Help script
To simplify test execution, the test-runner.sh script is available. You can find the corresponding documentation here: [Help script](scripts/README.md)