i'v tried this code
Triple t = NodeFactory.createURI(s,p,o);
context.add(t);
However, I cannot get this triple using sparql.
Related
I will apologise right at the outset as I am sure my question is elementary! I am not a database man but I have an idea and only a graph database is going to do it - so i am learning right from the very beginning. I am using Neo4j 2.3 and building the blocks of my structure in org charts which I then convert into Excel - I am comfortable with Excel, I am an Engineer!
I use CONCATENATE within Excel to build my Cypher statements and generating the nodes works perfectly, so far so good.
I then used the same technique to build the Cypher statements for the relationships and when I trialled it using a single Cypher Statement the relationship loads perfectly but when I try a set of statements I get a message saying that I need WITH between MATCH and MERGE.
I have read up the stuff about WITH and I can see that I am mixing read and write statements without separating them properly, I can also see that aliasing comes into it - but for the life of me I can't see how to deal with it!
The first sheet looks like this and this generates the nodes nicely:
:
The second sheet - for the relationships, looks like this:
Any help at all would be much appreciated!
Each of the statements your second sheet generates could be executed independently, since you don't reference any of the aliases from previous lines.
Or you could add a WITH to the end of each statement, clearing out the aliases in scope:
MATCH (a1{id:470}), (b1: {id: 48}) MERGE (a1)-[:HAS_ROD_ASSY]->(b1) WITH NULL AS _
MATCH (a2 {id:463}), (b2: {id: 584}) MERGE (a2)-[:ROD_FEATURES]->(b2) WITH NULL AS _
...
LOAD CSV
However, you might find the LOAD CSV functionality in Cypher easier to work with.
TL,DR: I need a query which gives me all nodes/relationships which contain a certain value (in my case a string, so much I know), without knowing which property(key) contains the string. I am using neo4j(latest version), meteor (latest version) and the meteor neo4j driver, which is recommended on the neo4j website for meteor.
Currently I am working (as part of my bachelor thesis) on a tool to visualize the output of any Cypher query on any database, regardless of the database contents.
So far I've managed to correctly display nodes/relationships which are coming out. My problem now is to visualize (get nodes and relationships to feed into my frontend) textual queries like (taken from the neo4j movie database, which I am using for development)
MATCH (tom:Person {name:"Tom Hanks"})-[:ACTED_IN]->(m)<-[:ACTED_IN]-(coActors)
RETURN coActors.name
This kind of queries only returns an array of strings and not whole nodes or relationships. I now need some way (preferably a Cypher query) to get all nodes which contain for example the string "Audrey Tatou".
The problem I've now run into is that I didn't find a way to write a query which doesn't need something like
MATCH n
WHERE Person.name = "some name"
Since I don't know anything about the contents of the database I cannot use
WHERE propertyName = "propertyValue"
since I only know the value but not the name of the property.
The only solution here will be to get every nodes with your label and check properties and values using reflection on client side.
Using cypher, the solution would be to get all properties and their values and parse their values using a foreach loop. Maybe you can do this, but I'm really not sure, it's a recent feature but you can still give a try.
Here is what I found for the cypher solution: How can I return all properties for a node using Cypher?
So, you have query that returns array of string.
In fact - you can receive almost anything as result. Cypher is capable to return just bare strings, that are not related to anything.
Long story short - you can't vizualize this data, because of this data nature. Best you can do is to represent them as table (or similar), like Neo4j browser do this.
But, there is (probably) solution for you. Neo4j has feature called Legacy indexing. And there you can find full text indexes. Maybe this can help you.
You can just use a driver that returns nodes and rels, or if you do the queries manually add resultDataContents entry
{statements:[{statement:"MATCH ..","resultDataContents",["graph"]}]}
to your payload and you get nodes and relationships back.
I have a requirement to fetch Price List Item records which adhere to the following requirements:
Filter by a specific PriceList
Filter by a specific currency
Filter by the Name of the related Product containing a given string
I got the first two points working no problem, but it feels like expanding doesn't cope well with filtering. I started from a "straight" query on Product entity:
.../ProductSet?$filter=substringof('sometext', Name)
Equivalent SQL (targeting the corresponding CRM filtered views for clarity):
SELECT * FROM FilteredProduct WHERE ProductNumber LIKE '%sometext%'
The above query works, I can tweak it and have no issues. However, if I attempt to move on to ProductPriceLevel (thus expanding the relationship with Product, which is product_price_levels) I end up with this:
.../ProductPriceLevelSet?$expand=product_price_levels&$filter=substringof('sometext', product_price_levels/Name)
Equivalent SQL (again, targeting the relevant filtered views):
SELECT * FROM FilteredProductPriceLevel PPL JOIN FilteredProduct P
ON PPL.ProductId = P.ProductId WHERE P.ProductNumber LIKE '%sometext%'
Which has two different outcomes I see:
If the $filter has no matches, it works fine and returns an empty result set
If the $filter matches something, I get an error
code: -2147220970
message: The result selector of the 'Join' operation must return an anonymous type of two properties.
AFAIK that's what happens when you hit a limitation of LINQ-to-CRM regarding using .Where() on multiple entities at once... doesn't seem relevant!
What's wrong with my query ?
NOTE: The CRM 2013 I'm using is On-Premise, without any update rollup / service pack.
ALSO NOTE: The equivalent SQL, as can be expected, works perfectly
I don't think CRM OData supports adding a filter on a joined entity. Try reversing the entity you're actually starting with, and add a path to the referencing entity:
ProductSet()?$filter=substringof('sometext',ProductNumber)&$expand=product_price_levels&$select=product_price_levels/*
P.S. If you have linqPad, this is the query I used to generate this:
from p in ProductSet
where p.ProductNumber.Contains("sometext")
select new { p.product_price_levels }
I'm trying to pile a load of Twitter data into Neo4J using the .Net Neo4JClient. It's essentially the same type of Twitter user data for each node, but some of the nodes have a different significance to others, hence I would like to label them differently.
(I'm brand new both to Neo4J and the client, too).
So I've been trying to label them like so:
var query = _client.Cypher
.Create("(primaryNode:nodeLabel {twitterUser})")
.WithParams(new { nodeLabel = "nodeType", twitterUser } );
query.ExecuteWithoutResults();
Note: I split out the ExecuteWithoutResults so I could debug the query, and it is registering the parameters OK. The documentation here:
https://github.com/Readify/Neo4jClient/wiki/cypher#explicit-parameters
... suggests that parameters can be created "at any point in the fluent query" - but the Neo documentation about parameters here:
http://docs.neo4j.org/chunked/1.8.2/cypher-parameters.html
... kind of suggests otherwise, that parameters are specifically for things like WHERE clauses, indexes and relationship Ids.
Anyway - when I execute the above, I get a shiny new node with the label "nodeLabel" - so the parameter ain't working. Could somebody clarify whether or not I'm just making a dumb newbie mistake?
You can call WithParams whenever you want in the query. That's what the Neo4jClient doco means about "at any point in the fluent query".
However, Neo4j only supports parameters in certain parts of the Cypher text. If the parameter would affect the query plan, it's not allowed.
In this case, you cannot use parameters for labels. You will need to actually construct the query dynamically if you want to do that.
Edit: Even if this was a supported place for parameters, you'd at least have to write {nodeLabel} in your Cypher instead of just nodeLabel.
My objective:
I have built a working controller action in MVC which takes user input for various filter criteria and, using PredicateBuilder (part of LinqKit - sorry, I'm not allowed enough links yet) builds the appropriate LINQ query to return rows from a "master" table in SQL with a couple hundred thousand records. My implementation of the predicates is totally inelegant, as I'm new to a lot of this, and under a very tight deadline, but it did make life easier. The page operates perfectly as-is.
To this, I need to add a Full-Text search filter. Understanding the way LINQ translates Contains to LIKE(%%), using the advice in Simon Blog: LINQ-to-SQL - Enabling Full-Text Searching, I've already prepared Table Functions in SQL to run Freetext queries on the relevant columns. I have 4 functions, to match the query against 4 separate tables.
My approach:
At the moment, I'm building the predicates (I'll spare you) for the initial IQueryable data object, running a LINQ command to return them, like so:
var MyData = DB.Master_Items.Where(outer);
Then, I'm attempting to further filter MyData on the Keys returned by my full-text search functions:
var FTS_Matches_Subtable_1 = (from tbl in DB.Subtable_1
join fts in DB.udf_Subtable_1_FTSearch(KeywordTerms)
on tbl.ID equals fts.ID
select tbl.ForeignKey);
... I have 4 of those sets of matches which I've tried to use to filter my original dataset in several ways with no success. For instance:
MyNewData = MyData.Where(d => FTS_Matches_Subtable_1.Contains(d.Key) ||
FTS_Matches_Subtable_2.Contains(d.Key) ||
FTS_Matches_Subtable_3.Contains(d.Key) ||
FTS_Matches_Subtable_4.Contains(d.Key));
I just get the error: The incoming tabular data stream (TDS) remote procedure call (RPC) protocol stream is incorrect. Too many parameters were provided in this RPC request. The maximum is 2100.
I get that it's because I'm trying to pass a relatively large set of data into the Contains function and LINQ is converting each record into a separate parameter, exceeding the limit.
I just don't know how to get around it.
I found another post linq expression to return property value which seemed SO promising. I tried ifwdev's solution (2nd highest ranked answer): using LinqKit to build an extension that will break up the queries into manageable chunks. But I can't figure out how to implement it. Out of my depth right now maybe?
Is there another approach that I'm missing? Some simpler way to accomplish this that I've overlooked?
Sorry for the long post. But thank you for any help you can provide!
This is a perfect time to go back to raw ado.net.
Twisting things around just to use linq to sql is probably just as time consuming if you wrote the query and hydration by hand.