# DgraphEx
[](https://travis-ci.org/elbow-jason/dgraph_ex) [![Hex Version][hex-img]][hex] [![License][license-img]][license]
[hex-img]: https://img.shields.io/hexpm/v/dgraph_ex.svg
[hex]: https://hex.pm/packages/dgraph_ex
[license-img]: http://img.shields.io/badge/license-MIT-brightgreen.svg
[license]: http://opensource.org/licenses/MIT
An elixir database wrapper for dgraph database.
Works with dgraph v0.8.1 (most current release as of 16 AUG 2017)
[Docs](https://hexdocs.pm/dgraph_ex)
##### Installation:
```elixir
def deps do
[{:dgraph_ex, "~> 0.1.5"}]
end
```
## Usage
#### define a model
```elixir
defmodule Person do
use DgraphEx.Vertex
vertex :person do
field :name, :string, index: [:exact, :term]
field :address, :string, index: [:exact, :term]
end
end
```
```elixir
defmodule Land do
use Vertex
vertex :land do
field :address, :string, index: [:exact, :term], count: true
field :zipcode, :string, index: [:exact], count: true
field :city, :string, index: [:exact], count: true
field :land_size, :int, index: true
field :living_space, :int, index: true
field :zoning, :string, index: [:exact], count: true
field :floors, :int
field :construction_year, :string
field :geo_center, :geo, index: [:geo]
field :geo_border, :geo, index: [:geo]
field :owner, :uid, model: Person, reverse: true
end
end
```
#### mutate the schema
```elixir
import DgraphEx
alias DgraphEx.Repo
{:ok, _} = Repo.request mutation(schema: Land)
{:ok, _} = Repo.request mutation(schema: Person)
```
#### define a changeset
```elixir
alias DgraphEx.Changeset
def changeset(%Person{} = model, changes) when is_map(changes) do
model
|> Changeset.cast(changes, _allowed_fields = [:name, :address])
|> Changeset.validate_required(_required_fields = [:name, :address])
|> Changeset.validate_type(_typed_fields = [:name, :address])
|> Changeset.uncast
end
```
#### insert a model
We apply the `changeset` function to ensure data consistency:
```elixir
{:ok, person} =
%Person{}
|> Person.changeset(%{name: "jason", address: "221B Baker St. London, England 55555"})
```
And `person` is:
```elixir
%Person{
_uid_: nil,
address: "221B Baker St. London, England 55555",
name: "jason",
}
```
Then we insert into the `Repo`:
```elixir
{:ok, person} = Repo.insert(person)
```
The resulting `person` is:
(notice the `_uid_` is populated)
```elixir
%Person{
_uid_: "0x11c",
address: "221B Baker St. London, England 55555",
name: "jason",
}
```
#### update a model
Using the `person` from above:
```elixir
{:ok, person} = Person.changeset(person, %{name: "John Lakeman"})
person = Repo.update(person)
```
#### get a model by `_uid_`.
```elixir
Repo.get(Company, "0x11c")
```
returns `nil` or a populated `%Company{}`
#### find anything
With function syntax:
```elixir
import DgraphEx
query()
|> func(:spy, eq(:name, "John Lakeman"))
|> select({
:_uid_,
:address,
:name,
})
|> Repo.request
```
Again with keyword (kwargs) syntax:
```elixir
import DgraphEx
alias DgraphEx.Repo
query([
get: :spy,
func: eq(:name, "John Lakeman"),
select: {
:_uid_,
:address,
:name,
},
]) |> Repo.request
```
Both of the above requests for "spy" result in the same response:
```elixir
{:ok, %{
"spy" => [
%{
"_uid_" => "0x11c",
"address" => "221B Baker St. London, England 55555",
"name" => "John Lakeman",
}
]
}}
```
