# `Gno.Store.Adapters.Qlever`
[🔗](https://github.com/rdf-elixir/gno/blob/v0.1.0/lib/gno/store_adapters/qlever.ex#L1)

A `Gno.Store.Adapter` implementation for [QLever](https://github.com/ad-freiburg/qlever).

QLever uses a single root endpoint for all SPARQL operations (query, update,
and Graph Store Protocol). Write operations require an access token.

## Manifest Configuration

    @prefix gno:  <http://gno.app/> .
    @prefix gnoa: <http://gno.app/ns/adapter/> .

    <Qlever> a gnoa:Qlever
        ; gno:storeEndpointScheme "http"          # optional (default: "http")
        ; gno:storeEndpointHost "localhost"       # optional (default: "localhost")
        ; gno:storeEndpointPort 7001              # optional (default: 7001)
        ; gnoa:qleverAccessToken "my-access-token"  # required for write operations
    .

## Default Graph Semantics

QLever uses union default graph semantics: the default graph is the union of all named
graphs and the real default graph. The adapter automatically normalizes this by setting
the `default-graph-uri` parameter to `<http://qlever.cs.uni-freiburg.de/builtin-functions/default-graph>`
for query operations.

## Unsupported Operations

QLever does not support the following SPARQL graph management operations:
LOAD, CLEAR, CREATE, ADD, COPY, MOVE.
Attempting these will return `{:error, %Gno.Store.UnsupportedOperationError{}}`.

# `t`

```elixir
@type t() :: %Gno.Store.Adapters.Qlever{
  __additional_statements__: term(),
  __id__: term(),
  access_token: term(),
  default_graph_semantics_config: term(),
  graph_store_endpoint: term(),
  host: term(),
  port: term(),
  query_endpoint: term(),
  scheme: term(),
  update_endpoint: term(),
  userinfo: term()
}
```

# `build`

# `build`

# `build!`

# `build!`

# `build_id`

# `from`

```elixir
@spec from(Grax.Schema.t()) :: {:ok, t()} | {:error, any()}
```

# `from!`

```elixir
@spec from!(Grax.Schema.t()) :: t()
```

# `graph_semantics`

Returns the graph semantics for a specific adapter instance.

Checks the `default_graph_semantics_config` manifest property first,
falling back to `default_graph_semantics/0`.

# `load`

```elixir
@spec load(
  RDF.Graph.t() | RDF.Description.t(),
  RDF.IRI.coercible() | RDF.BlankNode.t(),
  opts :: keyword()
) :: {:ok, t()} | {:error, any()}
```

# `load!`

```elixir
@spec load!(
  RDF.Graph.t() | RDF.Description.t(),
  RDF.IRI.coercible() | RDF.BlankNode.t(),
  opts :: keyword()
) :: t()
```

---

*Consult [api-reference.md](api-reference.md) for complete listing*