Blueprint41 Relationships - circles-arrows/blueprint41 GitHub Wiki

Blueprint41 Relationships

The following steps will guide you on how to load and update an instance of ACTED_IN relationship.

Load Relationships

There are 4 options on how to load the ACTED_IN relationship:

Load all ACTED_IN and filter via blueprint41 expression.
```
ACTED_IN.Where(alias => alias.Person(actor));
```
Load all ACTED_IN via actor only.
```
actor.ActedMovieRelations();
```

Load all ACTED_IN via actor and filter via blueprint41 expression.

actor.ActedMoviesWhere(alias => alias.roles == new string[] { "Thomas Anderson" });

Load all ACTED_IN via actor and json notation.

actor.ActedMoviesWhere(roles: new string[] { "Thomas Anderson" });

Updating a Relationship property

To update relationship values, use the Assign(jsonNotation) method.

To update the ACTED_IN relationship property, create the static method UpdateRelationships. In the method, create a transaction and get the Movie record by calling the Movie.LoadBytitle(string) and get Actor by calling the Person.LoadByname(string) method. Change the value of the ACTED_IN relationship roles property:

Property	Value
roles	"Thomas Anderson", "Neo", "The One"

For loading relationship, we can choose either option 3 or 4, because we only need to update the ACTED_IN relationship where the roles are "Thomas Anderson".

private static void UpdateRelationships()
{
    using (Transaction.Begin(true))
    {
        var actor = Person.LoadByname("Keanu Reeves");

        // Option 3 - Load ACTED_IN via actor and blueprint41 expression and assign new value via json notation.
        //actor.ActedMoviesWhere(alias => alias.roles == new string[] { "Thomas Anderson" })
        //     .Assign(roles: new string[] { "Thomas Anderson", "Neo", "The One" });

        // Option 4 - Load ACTED_IN via actor and json notation and assign new values via json notation.
        actor.ActedMoviesWhere(roles: new string[] { "Thomas Anderson" })
             .Assign(roles: new string[] { "Thomas Anderson", "Neo", "The One" });

        Transaction.Commit();
    }
}

In the Main method, call the UpdateRelationships method after the UpdateMovie method and before the GetMoviesAndTheActors method.

static void Main(string[] args)
{
    Driver.Neo4jPersistenceProvider provider = new Driver.Neo4jPersistenceProvider("bolt://localhost:7687", "[USERNAME_HERE]", "[PASSWORD_HERE]");
    PersistenceProvider.CurrentPersistenceProvider = provider;

    Datastore model = new Datastore();
    model.Execute(true);

    //CreateMoviesAndActors();

    //DeleteMovie("Cloud Atlas");

    //UpdateMovie();

    UpdateRelationships();

    GetMoviesAndTheActors();

    Console.ReadKey();
}

Press F5 to run the "MovieGraph" application. You've successfully updated the ACTED_IN relationship.

Get Relationships By Property Value

To get the ACTED_IN relationships by property value, create the static method GetRelationshipsByPropertyValue. In the method, create a transaction and get the ACTED_IN relationship by calling the ACTED_IN.Where(jsonNotation) or the ACTED_IN.Where(expression).

private static void GetRelationshipsByPropertyValue()
{
    using (Transaction.Begin())
    {
        Console.WriteLine($"\n Get relationship with roles: \"Thomas Anderson\", \"Neo\", \"The One\" ");

        foreach (var actedIn in ACTED_IN.Where(roles: new string[] { "Thomas Anderson", "Neo", "The One" }))
        {
            Console.WriteLine($" (in:Person {{ name: '{actedIn.Person.name}' }})-[rel:ACTED_IN {{ roles: [{string.Join(", ", actedIn.roles.Select(item => "'" + item + "'"))}] }}]-(out:Movie {{ title: '{actedIn.Movie.title}' }})");
        }

        Console.WriteLine($"\n Get relationship with roles: \"Neo\" ");

        foreach (var actedIn in ACTED_IN.Where(rel => rel.roles.Any("Neo")))
        {
            Console.WriteLine($" (in:Person {{ name: '{actedIn.Person.name}' }})-[rel:ACTED_IN {{ roles: [{string.Join(", ", actedIn.roles.Select(item => "'" + item + "'"))}] }}]-(out:Movie {{ title: '{actedIn.Movie.title}' }})");
        }
    }
}

In the Main method, call the GetRelationshipsByPropertyValue method after the GetMoviesAndTheActors method.

static void Main(string[] args)
{
    Driver.Neo4jPersistenceProvider provider = new Driver.Neo4jPersistenceProvider("bolt://localhost:7687", "[USERNAME_HERE]", "[PASSWORD_HERE]");
    PersistenceProvider.CurrentPersistenceProvider = provider;

    Datastore model = new Datastore();
    model.Execute(true);

    //CreateMoviesAndActors();
    
    //DeleteMovie("Cloud Atlas");

    //UpdateMovie();

    //UpdateRelationships();

    //GetMoviesAndTheActors();

    GetRelationshipsByPropertyValue();

    Console.ReadKey();
}

Press F5 to run the "MovieGraph" application.

Get `Actors` from a relationship and Add to a `Movie`

To get the actors from ACTED_IN relationship and add to a new Movie, create the static method GetActorsFromRelationshipAndAddToMovie. In the method, create a transaction and get the Movie record by calling the Movie.LoadBytitle(string) method and set movieTitle parameter value to "The Matrix Reloaded". After getting the record, load ACTED_IN relationship by calling the method matrix.ActorsWhere(jsonNotation).

private static void GetActorsFromRelationshipAndAddToMovie()
{
    using (Transaction.Begin(true))
    {
        var matrix = Movie.LoadBytitle("The Matrix Reloaded");

        var acted_in = matrix.ActorsWhere(roles: new string[] { "Morpheus" }).First();

        var laurence = acted_in.Person;

        acted_in = matrix.ActorsWhere(roles: new string[] { "Thomas Anderson", "Neo", "The One" }).First();

        var keanu = acted_in.Person;

        Movie johnWick2 = new Movie()
        {
            title = "John Wick: Chapter 2",
            tagline = "The Only Way Out Is Back In",
            released = 2017
        };

        johnWick2.AddActor(keanu, roles: new string[] { "John Wick" });
        johnWick2.AddActor(laurence, roles: new string[] { "Bowery King" });

        Transaction.Commit();
    }
}

In the Main method, call the GetActorsFromRelationshipAndAddToMovie method after the UpdateRelationships method and before the GetMoviesAndTheActors method.

static void Main(string[] args)
{
    Driver.Neo4jPersistenceProvider provider = new Driver.Neo4jPersistenceProvider("bolt://localhost:7687", "[USERNAME_HERE]", "[PASSWORD_HERE]");
    PersistenceProvider.CurrentPersistenceProvider = provider;

    Datastore model = new Datastore();
    model.Execute(true);

    //CreateMoviesAndActors();

    //DeleteMovie("Cloud Atlas");

    //UpdateMovie();

    //UpdateRelationships();

    GetActorsFromRelationshipAndAddToMovie();

    GetMoviesAndTheActors();

    //GetRelationshipsByPropertyValue();

    Console.ReadKey();
}

Press F5 to run the "MovieGraph" application.

🎉 You've successfully load and updated an ACTED_IN relationship. Next topic, we will change the way on how we get the Movie records by using Blueprint41 query.

Blueprint41 Relationships - circles-arrows/blueprint41 GitHub Wiki