/// <summary>
/// Creates a single large query for the creation of a node and it's direct relationships.
/// </summary>
/// <param name="model">The for which to create the creation query</param>
/// <returns>The query string for the creation of the node and its direct relationships</returns>
private string BuildNodeCreationQuery(BasicNodeModel model)
{
StringBuilder builder = new StringBuilder();
// Append the node creation statement
builder.AppendFormat(kNodeCreationStatement, model.GetNodeLabels());
builder.AppendLine();
// Append the relationship statements
BuildRelationshipMergeStatement(builder, model.Relationships, model.ContentType);
// Append the return statement
builder.Append("RETURN n");
return(builder.ToString());
}
/// <summary>
/// Adds the given node to the graph.
/// PRECONDITION: The node must be valid
/// </summary>
/// <param name="node">The BasicNodeModel of the node to add to the graph</param>
/// <returns>Returns true if the node was added to the graph successfully</returns>
public bool AddNode(BasicNodeModel node)
{
// The total number of nodes that should be created
int expectedNodeCount = node.Relationships.Where(x => x.IsNewAddition).Count() + 1;
int expectedRelationshipCount = node.Relationships.Count();
int actualNodeCount = 0;
int actualRelationshipCount = 0;
// Get the statements that need to be run
List <Statement> creationStatements = GenerateStatements(node);
// Create the session
using (ISession session = driver.Session())
{
// Add the source node
session.WriteTransaction(action =>
{
IStatementResult nodeResult = action.Run(new Statement($"CREATE (s:{node.GetNodeLabels()} $props)",
new Dictionary <string, object> {
{ "props", node.GetPropertyMap() }
}));
actualNodeCount += nodeResult.Summary.Counters.NodesCreated;
// Only continue if the node was added
if (actualNodeCount == 1)
{
// For each of the relationship statements,
foreach (Statement relStatement in creationStatements)
{
// Run the statement
IStatementResult relResult = action.Run(relStatement);
// Update the counts of the actual node and relationship values
actualNodeCount += relResult.Summary.Counters.NodesCreated;
actualRelationshipCount += relResult.Summary.Counters.RelationshipsCreated;
}
}
// If the node and relationship counts do not equal the expected values,
if (actualNodeCount != expectedNodeCount || actualRelationshipCount != expectedRelationshipCount)
{
// This transaction has failed
action.Failure();
}
else
{
// This transaction has succeeded
action.Success();
}
});
}
return(actualNodeCount == expectedNodeCount && actualRelationshipCount == expectedRelationshipCount);
}