Cypher 工作流

// Create a company node
private IResultSummary AddCompany(IQueryRunner tx, string name)
{
    return tx.Run("CREATE (a:Company {name: $name})", new { name }).Consume();
}

// Create a person node
private IResultSummary AddPerson(IQueryRunner tx, string name)
{
    return tx.Run("CREATE (a:Person {name: $name})", new { name }).Consume();
}

// Create an employment relationship to a pre-existing company node.
// This relies on the person first having been created.
private IResultSummary Employ(IQueryRunner tx, string personName, string companyName)
{
    return tx.Run(
            @"MATCH (person:Person {name: $personName}) 
                 MATCH (company:Company {name: $companyName}) 
                 CREATE (person)-[:WORKS_FOR]->(company)",
            new { personName, companyName })
        .Consume();
}

// Create a friendship between two people.
private IResultSummary MakeFriends(IQueryRunner tx, string name1, string name2)
{
    return tx.Run(
            @"MATCH (a:Person {name: $name1}) 
                 MATCH (b:Person {name: $name2})
                 MERGE (a)-[:KNOWS]->(b)",
            new { name1, name2 })
        .Consume();
}

// Match and display all friendships.
private int PrintFriendships(IQueryRunner tx)
{
    var result = tx.Run("MATCH (a)-[:KNOWS]->(b) RETURN a.name, b.name");

    var count = 0;
    foreach (var record in result)
    {
        count++;
        Console.WriteLine($"{record["a.name"]} knows {record["b.name"]}");
    }

    return count;
}

public void AddEmployAndMakeFriends()
{
    // To collect the session bookmarks
    var savedBookmarks = new List<Bookmarks>();

    // Create the first person and employment relationship.
    using (var session1 = Driver.Session(o => o.WithDefaultAccessMode(AccessMode.Write)))
    {
        session1.ExecuteWrite(tx => AddCompany(tx, "Wayne Enterprises"));
        session1.ExecuteWrite(tx => AddPerson(tx, "Alice"));
        session1.ExecuteWrite(tx => Employ(tx, "Alice", "Wayne Enterprises"));

        savedBookmarks.Add(session1.LastBookmarks);
    }

    // Create the second person and employment relationship.
    using (var session2 = Driver.Session(o => o.WithDefaultAccessMode(AccessMode.Write)))
    {
        session2.ExecuteWrite(tx => AddCompany(tx, "LexCorp"));
        session2.ExecuteWrite(tx => AddPerson(tx, "Bob"));
        session2.ExecuteWrite(tx => Employ(tx, "Bob", "LexCorp"));

        savedBookmarks.Add(session2.LastBookmarks);
    }

    // Create a friendship between the two people created above.
    using (var session3 = Driver.Session(
               o =>
                   o.WithDefaultAccessMode(AccessMode.Write).WithBookmarks(savedBookmarks.ToArray())))
    {
        session3.ExecuteWrite(tx => MakeFriends(tx, "Alice", "Bob"));

        session3.ExecuteRead(PrintFriendships);
    }
}

public long AddPerson(string name)
{
    using var session = Driver.Session();
    session.ExecuteWrite(tx => CreatePersonNode(tx, name));
    return session.ExecuteRead(tx => MatchPersonNode(tx, name));
}

private static IResultSummary CreatePersonNode(IQueryRunner tx, string name)
{
    return tx.Run("CREATE (a:Person {name: $name})", new { name }).Consume();
}

private static long MatchPersonNode(IQueryRunner tx, string name)
{
    var result = tx.Run("MATCH (a:Person {name: $name}) RETURN id(a)", new { name });
    return result.Single()[0].As<long>();
}