Setting up an Entity Model

This article is about the RDF Entity Framework. It shows you how to setup a basic entity model using Semantics.Server. Setting up Semantics.Server The first step to setting up an entity model is configuing a Semantics.Server database with the graphs that you will need to hold your entity model. We will use the Semantics.Server API in the Semantics.SDK to do this. Create a provider graph that will hold the information about your model setup.

SemanticServerModel entityStore = new SemanticServerModel(ConnectionString);

entityStore.Graphs.CreateMultiGraph("http://entitystore/graph-provider");

Create a graph to hold the facts about the entity instances.

entityStore.Graphs.CreateGraph("http://entitystore/graph-fact");

Create a graph to hold facts about the ontology.

entityStore.Graphs.CreateGraph("http://entitystore/graph-ontology");

Create a rulebase for your CBD description type.

entityStore.Rulebases.CreateRulebase("http://entitystore/rulebase-cbd-description", EntityProviderRulebase.ConciseBoundedDescription);

Setting up the Entity Model We will use the ModelSetup helper class to defined a entity model for the Semantics.Server database we just setup. First we define a URI for our model.

ModelSetup modelSetup = new ModelSetup("http://entitystore/model/model-1");

Map the fact graph into the entity model. This connects the logic graph name with the physical name.

GraphSetup factGraph = new GraphSetup(EntityGraphUri.Fact, true);
factGraph.AddTarget("http://entitystore/graph-fact");
modelSetup.AddGraph(factGraph);

Map the ontology graph into the entity model.

GraphSetup ontologyGraph = new GraphSetup(EntityGraphUri.Ontology, true);
ontologyGraph.AddTarget("http://entitystore/graph-ontology");
modelSetup.AddGraph(ontologyGraph);

Map the description graph onto the fact graph since we are not using any other entity data graphs in this model.

GraphSetup descriptionGraph = new GraphSetup(EntityGraphUri.Description);
descriptionGraph.AddTarget("http://entitystore/graph-fact");
modelSetup.AddDefaultGraph(descriptionGraph);

Create a description type based on our CBD rules.

DescriptionTypeSetup cbdType = new DescriptionTypeSetup("http://entitystore/model/model-1/type-default");
cbdType.AddRulebase("http://entitystore/rulebase-cbd-description");
modelSetup.AddDefaultDescriptionType(cbdType);

Create the entity model.

SemanticServerProvider provider = new SemanticServerProvider(ConnectionString);
provider.Settings.ProviderGraphUri = "http://entitystore/graph-provider";
EntityModel model = modelSetup.CreateEntityModel(provider);

That's it.