Should I use Collection or List or a regular array for Neo4jClient? - neo4jclient

Question

I saw some code on StackOverflow of people using Collection<> for the Neo4jClient , but I couldnt find that in any namespace.
Furthermore, I couldnt find any mention of arrays or collections on the Github page. I'm brand new to Neo4jClient so excuse the newbie question (if it is so)
So, can someone tell me how to use an array in Neo4jClient with C# ? Include any namespaces if necessary.
I'm talking about serializing an array (e.g.: string [], List, or Collection<>)
Thanks

Answer 1

The final step of a Cypher query, .Results returns an IEnumerable. You can do anything you want with it. Each time you enumerate it, it will run the query against Neo4j.
For example,
var users = client.Cypher
.Match("(user:User)")
.Return(user => user.As<User>())
.Results;
foreach (var user in users) // The query actual runs here
{
}
This means that if you enumerated through it twice, you would actually run the query against the database twice:
For example,
var users = client.Cypher
.Match("(user:User)")
.Return(user => user.As<User>())
.Results;
foreach (var user in users) // The query actual runs here
{
}
foreach (var user in users) // And then it runs again here
{
}
Now, that's not usually what you want. You don't want to send the extra call to the database, and you don't want the risk of the data changing.
To get around this, people will often force it to enumerate early by using either ToArray() or ToList(). These come from System.Linq.
For example,
var users = client.Cypher
.Match("(user:User)")
.Return(user => user.As<User>())
.Results
.ToList(); // The query runs here now
foreach (var user in users) // This just enumerates the in-memory list
{
}
foreach (var user in users) // This just enumerates the in-memory list
{
}
None of this is specific to Neo4jClient: it's just how enumerables work in .NET.