I'm a beginner in Breeze and have a problem with the following situation
I have the following model. A Person entity, can have multiple Projects assigned. A project can have multiple Tasks. And each Task has a Priority. I would like to get all the Persons which have at least one Project which has at least one Task with a Priority code 'High'.
I found I can use the 'any' or 'some' for working with 2nd level children.
var p1 = new breeze.Predicate.create('projects', 'some', 'client.code', 'Equals', 'ABC');
The above correctly returns Persons with Projects for Clients with code ABC. But in my case I would have to apply the 'any' one level deep, also to Tasks and I can't find the correct way of doing it.
Thanks for any help
You can nest multiple any/all using that syntax:
var query = breeze.EntityQuery.from('persons')
var p = new breeze.Predicate('projects', 'any', new breeze.Predicate('tasks','any','priority','>',1));
query = query.where(p);
You'll have to change the MaxAnyAllExpressionDepth property of your controller to allow multiple any level:
[BreezeNHController(MaxAnyAllExpressionDepth = 5)]
Related
Following the question I asked: Build a dynamic query using neo4j client
I got an answer about how can I return value dynamically using string only.
When I'm trying to use the syntax to return multi values from the query it failed,
I tried the following query:
var resQuery2 = WebApiConfig.GraphClient.Cypher
.Match("(movie:Movie {title:{title}})")
.OptionalMatch("(movie)<-[r]-(person:Person)")
.WithParam("title", title)
.Return(() => Return.As<string>("movie, collect([person.name, head(split(lower(type(r)), '_')), r.roles])"));
I'm getting the following error:
The deserializer is running in single column mode, but the response
included multiple columns which indicates a projection instead. If
using the fluent Cypher interface, use the overload of Return that
takes a lambda or object instead of single string. (The overload with
a single string is for an identity, not raw query text: we can't map
the columns back out if you just supply raw query text.)
Is it possible to return multiple nodes using only strings?
We can't get an output like in the question you asked previously - this is due to the fact that you are asking for a Node (the movie) and a Collection of strings (the collect) and they have no common properties, or even styles of property.
Firstly, let's look at the painful way to do this:
var q = gc.Cypher
.Match("(movie:Movie)")
.OptionalMatch("(movie)<-[r]-(person:Person)")
.Return(() => Return.As<string>("{movie:movie, roles:collect([person.name, head(split(lower(type(r)), '_')), r.roles])}"));
var results = q.Results;
Here we take the query items (movie, r, person) and create a type with them the {} around the results, and cast that to a string.
This will give you a horrible string with the Node data around the movie and then a collection of the roles:
foreach (var m in results)
{
//This is going to be painful to navigate/use
dynamic d = JsonConvert.DeserializeObject<dynamic>(m);
Console.WriteLine(d.movie);
Console.WriteLine(d.roles);
}
You'd be a lot better off doing something like:
var q = gc.Cypher
.Match("(movie:Movie)")
.OptionalMatch("(movie)<-[r]-(person:Person)")
.Return(() => new
{
Movie = Return.As<Node<string>>("movie"),
Roles = Return.As<IEnumerable<string>>("collect([person.name, head(split(lower(type(r)), '_')), r.roles])")
});
var res = q.Results;
You could either JsonConvert.DeserializeObject<dynamic>() the Movie node, at your leisure, or write a strongly typed class.
In terms of a 'dynamic' object, I don't know how you were wanting to interact with the collect part of the return statement, if this doesn't help, you might need to update the question to show a usage expectation.
I have the following python code to make a graph in neo4j. I am using py2neo version 2.0.3.
import json
from py2neo import neo4j, Node, Relationship, Graph
graph = neo4j.Graph("http://localhost:7474/db/data/")
with open("example.json") as f:
for line in f:
while True:
try:
file = json.loads(line)
break
except ValueError:
# Not yet a complete JSON value
line += next(f)
# Now creating the node and relationships
news, = graph.create(Node("Mainstream_News", id=unicode(file["_id"]), entry_url=unicode(file["entry_url"]),
title=unicode(file["title"]))) # Comma unpacks length-1 tuple.
authors, = graph.create(
Node("Authors", auth_name=unicode(file["auth_name"]), auth_url=unicode(file["auth_url"]),
auth_eml=unicode(file["auth_eml"])))
graph.create(Relationship(news, "hasAuthor", authors ))
I can create a graph with nodes Mainstream_News and Authors with a relation 'hasAuthor'. My problem is when I am doing this I am having one Mainstream_News node with one Authors but in reality one author nodes has more than one Mainstream_News. I would like to make auth_name property of a Author nodes as a index to connect with the Mainstream_news nodes. Any suggestions will be great.
You are creating a new Authors node each time through your loop, even if an Author node (with the same properties) already exists.
First, I think you should create uniqueness constraints on Authors(auth_name) and Mainstream_News(id), to enforce what seem to be your requirements. This only needs to be done once. A uniqueness constraint also creates an index for you automatically, which is a bonus.
graph.schema.create_uniqueness_constraint("Authors", "auth_name")
graph.schema.create_uniqueness_constraint("Mainstream_News", "id")
But you will probably have to empty out your DB first (at least of all Authors and Mainstream_News nodes and their relationships), since I presume it currently has a lot of duplicate nodes.
Then, you can use the merge_one and create_unique APIs to prevent duplicate nodes and relationships:
news = graph.merge_one("Mainstream_News", "id", unicode(file["_id"]))
news.properties["entry_url"] = unicode(file["entry_url"])
news.properties["title"] = unicode(file["title"])
authors = graph.merge_one("Authors", "auth_name", unicode(file["auth_name"]))
news.properties["auth_url"] = unicode(file["auth_url"])
news.properties["auth_eml"] = unicode(file["auth_eml"])
graph.create_unique(Relationship(news, "hasAuthor", authors))
This is what I normally do, as I find it easier to know what's happening. As far as I know there are a but when you create_unique with only a Node, and there are no need to create the nodes, when you also have to create an edge.
I don't have the database on this computer, so please bear with me, if there are some typo'es, I'll correct it in the morning, but I guess you'll rather have a fast answer.. :-)
news = graph.cypher.execute_one('MATCH (m:Mainstream_News) '
'WHERE m.id = {id} '
'RETURN p'.format(id=unicode(file["_id"])))
if not news:
news = Node("Mainstream_News")
news.properties['id] = unicode(file["_id"])
news.properties['entry_url'] = unicode(file["entry_url"])
news.properties['title'] = unicode(file["title"])
# You can make a for-loop here
authors = Node("Authors")
authors.properties['auth_name'] = unicode(file["auth_name"])
authors.properties['auth_url'] = unicode(file["auth_url"])
authors.properties['auth_eml'] = unicode(file["auth_eml"])
rel = Relationship(new, "hasAuthor", authors)
graph.create_unique(rel)
# For-loop should end here
I've included the tree first lines, to make it more generic. It returns a node-object or None.
EDIT:
#cybersam use of schema is cool, implement that to, I'll try to use it myselfe also.. :-)
You can read more about it here:
http://neo4j.com/docs/stable/query-constraints.html
http://py2neo.org/2.0/schema.html
im trying to figure out how to Count all Items from child to child where a column called "IsVerified" is true. I got the first two childs counted (BlogPost -> Comments(child) -> SubComments(child)) but i cant figure out how to count the third child
The structure of the model is similar to this on
BlogPost -> Comments -> SubComments -> SubSubComments
I cant show you the real models so here is an example:
https://gist.github.com/anonymous/c357bfdd158cc6a392d9
Its all working instead of the third child.
I hope you can help me.
Thanks.
Something like:
// Don't need ToList here, lazy is fine
var blogs = db.BlogPosts.Include("Comments.SubComments.SubSubComments");
var count = blogs.SelectMany(b => b.Comments)
.Where(c => c.IsVerified)
.SelectMany(c => c.SubComments)
.Where(sc => sc.IsVerifier)
.Count();
will get the count of verified sub-comments in verified sub-comments.
And because I've not used ToList on the initial expression this should all be converted to SQL and executed on the server (details of the SQL will depend on the details of the model, for example whether relationships are required or not).
in Neo4j 2.0 M06 I understand that CREATE UNIQUE is depreciated and replaced with MERGE and MATCH instead, but I am finding it hard to see how this can be used to create a unique path.
as an example, I want to create a
MERGE root-[:HAS_CALENDER]->(cal:Calender{name:'Booking'})-[:HAS_YEAR]->(year:Year{value:2013})-[:HAS_MONTH]-(month:Month{value:'January'})-[:HAS_DAY]->(day:Day{value:1})
ON CREATE cal
SET cal.created = timestamp()
ON CREATE year
SET year.created = timestamp()
ON CREATE month
SET month.created = timestamp()
ON CREATE day
SET day.created = timestamp()
intention is that when I try to add a new days to my calender, it should only create the year, and month when it does not exist else just add to the existing path. Now when i run the query, i get an STATEMENT_EXECUTION_ERROR
MERGE only supports single node patterns
should I be executing multiple statements here to achieve this.
So the question is what's the best way in Neo4j to handle cases like this?
Edit
I did change my approach a bit and now even after making multiple calls, I think my merge is happening at a label level and not trying to restrict to the start node I provide as a result I am ending up with nodes that are shared across years and month which is not what I was expecting
I would really appreciate if some one can suggest me how to get a proper graph like below
my c# code is somewhat like this:
var qry = GraphClient.Cypher
.Merge("(cal:CalendarType{ Name: {calName}})")
.OnCreate("cal").Set("cal = {newCal}")
.With("cal")
.Start(new { root = GraphClient.RootNode})
.CreateUnique("(root)-[:HAS_CALENDAR]->(cal)")
.WithParams(new { calName = newCalender.Name, newCal = newCalender })
.Return(cal => cal.Node<CalenderType>());
var calNode = qry.Results.Single();
var newYear = new Year { Name = date.Year.ToString(), Value = date.Year }.RunEntityHousekeeping();
var qryYr = GraphClient.Cypher
.Merge("(year:Year{ Value: {yr}})")
.OnCreate("year").Set("year = {newYear}")
.With("year")
.Start(new { calNode })
.CreateUnique("(calNode)-[:HAS_YEAR]->(year)")
.WithParams(new { yr = newYear.Value, newYear = newYear })
.Return(year => year.Node<Year>());
var yearNode = qryYr.Results.Single();
var newMonth = new Month { Name = date.Month.ToString(), Value = date.Month }.RunEntityHousekeeping();
var qryMonth = GraphClient.Cypher
.Merge("(mon:Month{ Value: {mnVal}})")
.OnCreate("mon").Set("mon = {newMonth}")
.With("mon")
.Start(new { yearNode })
.CreateUnique("(yearNode)-[:HAS_MONTH]->(mon)")
.WithParams(new { mnVal = newMonth.Value, newMonth = newMonth })
.Return(mon => mon.Node<Month>());
var monthNode = qryMonth.Results.Single();
var newDay = new Day { Name = date.Day.ToString(), Value = date.Day, Date = date.Date }.RunEntityHousekeeping();
var qryDay = GraphClient.Cypher
.Merge("(day:Day{ Value: {mnVal}})")
.OnCreate("day").Set("day = {newDay}")
.With("day")
.Start(new { monthNode })
.CreateUnique("(monthNode)-[:HAS_DAY]->(day)")
.WithParams(new { mnVal = newDay.Value, newDay = newDay })
.Return(day => day.Node<Day>());
var dayNode = qryDay.Results.Single();
Regards
Kiran
Nowhere on the documentation page does it say that CREATE UNIQUE has been deprecated.
MERGE is just a new approach that's available to you. It enables some new scenarios (matching based on labels, and ON CREATE and ON MATCH triggers) but also does not cover more complex scenarios (more than a single node).
It sounds like you're already familiar with CREATE UNIQUE. For now, I think you should still be using that.
It seems to me the picture of what you want your graph to look like has the order imposed by relationships, but your code models the order with nodes. If you want that graph, you will need to use relationship types like [2010], [2011] instead of a pattern like [HAS_YEAR]->({value:2010}).
Another way to say the same thing: you are trying to constitute uniqueness for a node intrinsically, by a combination of label and property, e.g. (unique:Day {value:4}). Assuming you have the relevant constraints, this would be database wide uniqueness, so only one fourth-day-of-the-month for all the months to share. What you want is extrinsic local uniqueness, uniqueness established and extended transitively by a hierarchy of relationships. Uniqueness for a node is then not in its internal properties but in its external 'position' or 'order' in relation to its parent. The locally unique pattern (month)-[:locally_unique_rel]->(day) is made unique for a wider scope when the month is made unique, and the month is made unique, not by property and label, but extrinsically by its 'order' or 'position' under its year. Hence the transitivity. I think this is a strength of modeling with graphs, among other things it allows you to continue to partition your structure. If for instance you want to split some of your days into AM and PM or into hours, you can easily do so.
So, in your graph, [HAS_DAY] makes all days equally related to their month, and cannot therefore be used to differentiate between them. You have solved this locally under a month, since the property value differentiates, but since the fourth-day-of-the-month in
(november)-[:HAS_DAY]->(4th)` and `(december)-[:HAS_DAY]->(4th)
are not distinct by property value or label, they are the same node in your graph. Locally, under a month say, unique nodes can be achieved equally with
[11]->()-[4]->(unique1), [11]->()-[5]->(unique2)
and
[HAS_MONTH]->({value:11})-[HAS_DAY]->(unique1 {value:4}),
[HAS_MONTH]->({value:11})-[HAS_DAY]->(unique2 {value:5})
The difference is that with the former extrinsic local uniqueness, you have the benefit of transitivity. Since the months are unique in a year, as (november) in [11]->(november) is locally unique, therefore the days of November are also unique in that year - the (fourth) node is distinct between
[11]->(november)-[4]->(fourth)
and
[12]-(december)->[4]->(fourth)
What this amounts to is transferring more of your semantic model to your relationships, leaving the nodes for storing data. The node identifiers in the picture you posted are only pedagogical, replacing them with x,y,z or empty parentheses would perhaps better reveal the structure or scaffolding of the graph.
If you want to keep the relationship types intact, adding an ordering property to each relationship to create a pattern like (november)-[:HAS_DAY {order:4}]->(4th) will also work. This may be less performant for querying, but you may have other concerns that make it worth it.
This code allows you to create calendar graphs on demand upon creation of an event for a specific day. You'll want to modify it to allow events on multiple days, but it seems more like your issue is creating unique paths, right? And you'd probably want to modify this to use parameters in your language of choice.
First I create the root:
CREATE (r:Root {id:'root'})
Then use this reusable MERGE query to successively match or create subgraphs for the calendar. I pass along the root so I can display the graph at the end:
MATCH (r:Root)
MERGE r-[:HAS_CAL]->(cal:Calendar {id:'General'})
WITH r,cal MERGE (cal)-[:HAS_YEAR]->(y:Year {id:2011})
WITH r,y MERGE (y)-[:HAS_MONTH]->(m:Month {id:'Jan'})
WITH r,m MERGE (m)-[:HAS_DAY]->(d:Day {id:1})
CREATE d-[:SCHEDULED_EVENT]->(e:Event {id:'ev3', t:timestamp()})
RETURN r-[*1..5]-()
Creates a graph like this when called multiple times:
Does this help?
I have a domain class called Order and that class has hasMany relation with Item class.
When I am querying for the list of orders with certain restrictions I am getting as many instances of Order as there are items.
So for example Order instance has say references to 3 instances of Item then , criteria call on Order is returning 3 duplicate instances of Order. I am not sure but if it's worth mentioning that the domain class Order has fetchMode set to "eager".
I am really puzzled with what's going on there. Any help in this regard will be greatly appreciated. Snippet of code is attached:
def clazz = "cust.Order"
def criteria = clazz.createCriteria()
println("clazz == "+Order.list())// returning correct data i.e unique instance of order
def filter = {
// trimmed down all filtering criteria for debugging
}//close filter
List results = criteria.list(max:params?.max,offset:params?.offset,filter)
results.each{Object data->
println(data.getClass())
}
println("results == "+results)
Thanks again
One solution is to use this inside your query:
resultTransformer org.hibernate.Criteria.DISTINCT_ROOT_ENTITY
If you call criteria.listDistinct instead of criteria.list duplicates will be eliminated
Criteria API is just a wrapper for constructing a SQL query. In your case, the query in question has JOINs in it (because of the eager fetching), and returns a cartesian product of Orders and their matching Items. Each row returned is included in results as a separate Order instance.
The easiest way to remove duplicates is to put all the results in a Set, like this:
def resultSet = new HashSet()
resultSet.addAll(results)
println("results == " + resultSet)
You could also use dynamic finders, as in Order.findAllBy* .Depending on how complicated your filter is, this could be easy or tough :)