private string RemoveNodeAndChildrenCypher <T>(GraphInterfaces.IField field)
{
string nodeName = typeof(T).Name.ToLowerInvariant();
return(_cypherBuilderFactory
.NewCypherBuilder()
.AddMatch(new[] { new Match {
Pattern = $"(({nodeName[0]}:{nodeName}{{{field.Name}:'{field.Value}'}})-[*0..]->(x))"
} })
.AddDetachDelete("x")
.ToString());
}
private string DeleteRelationshipCypher <A, B>(string relationShipName, GraphInterfaces.IField left, GraphInterfaces.IField right)
{
string objectAName = typeof(A).Name.ToLowerInvariant();
string objectBName = typeof(B).Name.ToLowerInvariant();
return(_cypherBuilderFactory
.NewCypherBuilder()
.AddMatch(new[] { new Match {
Pattern = $"(a: {objectAName})-[r:{relationShipName}]->(b: {objectBName})"
} })
.AddWhere($"a.{left.Name} = '{left.Value}' and b.{right.Name} = '{right.Value}'")
.AddDelete("r")
.ToString());
}
private string GetAllCypher <TNode>(GraphInterfaces.IField field, IEnumerable <string> relationships)
where TNode : class
{
string node = typeof(TNode).Name.ToLowerInvariant();
return(_cypherBuilderFactory.NewCypherBuilder()
.AddMatch(new[] { new Match {
Pattern = $"(e:{node})"
} })
.AddWhere($"e.{field.Name} = '{field.Value}'")
.AddMatch(new[] { new MatchWithAlias {
Alias = "path", Pattern = $"(e) <-[{string.Join('|',relationships.Select(_ => $":{_}"))} *]-()"
} })
.AddReturn(new[] { "e, path" })
.ToString());
}
private string GetCircularDependencyCypher <TNode>(string relationShip, GraphInterfaces.IField field)
{
string nodeName = typeof(TNode).Name.ToLowerInvariant();
return(_cypherBuilderFactory
.NewCypherBuilder()
.AddMatch(new[] { new Match {
Pattern = $"(e:{nodeName})"
} })
.AddWhere($"SIZE((e)<-[:{relationShip}] - ()) <> 0")
.AddAnd($"SIZE(()<-[:{relationShip}] - (e)) <> 0")
.AddAnd($"e.{field.Name} = '{field.Value}'")
.AddMatch(new[] { new MatchWithAlias {
Alias = "path", Pattern = $"(e) <-[:{relationShip} *]-(e)"
} })
.AddReturn(new[] { "e, path" })
.ToString());
}
public async Task <IEnumerable <Entity <TNode> > > GetAllEntities <TNode>(GraphInterfaces.IField field, IEnumerable <string> relationships)
where TNode : class
{
IAsyncSession session = AsyncSession();
try
{
string cypher = GetAllCypher <TNode>(field, relationships);
List <IRecord> records = await session.ReadTransactionAsync(tx => RunCypherWithResults(tx, cypher));
return(records?.Select(_ => new Entity <TNode> {
Node = _[0].As <INode>().Properties.AsJson().AsPoco <TNode>(), Relationships = Transform(_[1].As <IPath>())
}));
}
finally
{
await session.CloseAsync();
}
}
public async Task DeleteRelationship <A, B>(string relationShipName, GraphInterfaces.IField left, GraphInterfaces.IField right)
{
string cypher = DeleteRelationshipCypher <A, B>(relationShipName, left, right);
await ExecuteCypher(cypher);
}
public async Task DeleteNode <T>(GraphInterfaces.IField field)
{
string cypher = RemoveNodeCypher <T>(field.Name, field.Value);
await ExecuteCypher(cypher);
}