I tried many things but of no use.
I have already raised a question on stackoverflow earlier but I am still facing the same issue.
Here is the link to old stackoverflow question
creating multiple nodes with properties in json in neo4j
Let me try out explaining with a small example
This is the query I want to execute
{
"params" : {
"props" : [
{
"LocalAsNumber" : 0,
"NodeDescription" : "10TiMOS-B-4.0.R2 ",
"NodeId" : "10.227.28.95",
"NodeName" : "BLR_WAO_SARF7"
}
]
},
"query" : "MATCH (n:Router) where n.NodeId = {props}.NodeId RETURN n"}
For simplicity I have added only 1 props array otherwise there are around 5000 props. Now I want to execute the query above but it fails.
I tried using (props.NodeId}, {props[NodeID]} but everything fails.
Is it possbile to access a individual property in neo4j?
My prog is in c++ and I am using jsoncpp and curl to fire my queries.
If you do {props}.nodeId in the query then the props parameter must be a map, but you pass in an array. Do
"props" : {
"LocalAsNumber" : 0,
"NodeDescription" : "10TiMOS-B-4.0.R2 ",
"NodeId" : "10.227.28.95",
"NodeName" : "BLR_WAO_SARF7"
}
You can use an array of maps for parameter either with a simple CREATE statement.
CREATE ({props})
or if you loop through the array to access the individual maps
FOREACH (prop IN {props} |
MERGE (i:Interface {nodeId:prop.nodeId})
ON CREATE SET i = prop
)
Does this query string work for you?
"MATCH (n:Router) RETURN [p IN {props} WHERE n.NodeId = p.NodeId | n];"
Related
I have a Neo4j DB with relationships that have properties such as [:FRIENDS {since: "11/2015"}]. I need to represent the "since" property in the GraphQl Schema. RELAY has something call "edges" an apparently this is how they implement this feature but I am not using RELAY.....I didn't see anything in Apollo (maybe I missed it). Can someone show me how to do this?
Ok...so in order to get what I wanted which was to present both the node and the relationship (edge) to graphql I did what I would call a work-around by returning object.assign(node,relationship) to graphql....the downside is that I have to define a type nodeRel {} to receive the combined objects but it works. Also, the node and relationship objects can't have similar named properties. I can now answer the question how long John and Mary are friends or what groups John belongs to and how long he has been a member....Schema snippet:
... memberOf : [Group]
groupStatus : [MemberProfile]
attended : [Meeting]
submittedReport : [Report]
post : [Post]
}
type MemberProfile {
name : String
location : String
created : String
since : String
role : String
financial : Boolean
active : Boolean
}
Resolver:
groupStatus(voter) {
let session = driver.session(),
params = { voterid: voter.voterid },
query = `
MATCH (v:Voter)-[r:MEMBER_OF]->(g:Group)
WHERE v.voterid = $voterid
RETURN g AS group,r AS rel;
`
return session
.run(query, params)
.then(result => {
return result.records.map(record => {
return Object.assign(record.get("group").properties, record.get("rel").properties)
})
})
},
I hope this help someone else....
I am trying to create multiple nodes in Neo4j using Cypher by passing properties as parameters as part of an UNWIND function, but I keep receiving the error Type mismatch: expected Collection<T> but was Map.
This happens even when using the following example from the Neo4j documentation (link):
UNWIND {
props : [ {
name : "Andres",
position : "Developer"
}, {
name : "Michael",
position : "Developer"
} ]
} AS map
CREATE (n)
SET n = map
Can anyone point out what I am doing wrong here?
Note, the example above is not exactly as in the Neo4j documentation. Their example wraps the property names in double quotes, but this causes my instance of Neo4j to throw the errorInvalid input '"': expected whitespace...)
UNWIND is expecting a collection, not a map as you're currently passing in, try this instead (just remove the wrapping curly braces and prop top level field):
UNWIND [ {
name : "Andres",
position : "Developer"
}, {
name : "Michael",
position : "Developer"
} ] AS map
CREATE (n)
SET n = map
Chris's answer is of course the correct one, but here's why your solution doesn't work when you're following the documentation: you're not copying the documentation.
The documentation shows the use of a named parameter:
UNWIND { props } AS map
CREATE (n)
SET n = map
with props passed in the map of parameters, which would look like:
{
"props" : [ {
"name" : "Andres",
"position" : "Developer"
}, {
"name" : "Michael",
"position" : "Developer"
} ]
}
if you displayed the map as JSON. It means the {props} placeholder will be replaced by the value for the props key. Which is exactly what Chris did.
Here's what the Java code would look like:
GraphDatabaseService db = /* init */;
Map<String, Object> andres = new HashMap<>();
andres.put("name", "Andres");
andres.put("position", "Developer");
Map<String, Object> michael = new HashMap<>();
michael.put("name", "Michael");
michael.put("position", "Developer");
Map<String, Object> params = new HashMap<>();
params.put("props", Arrays.asList(andres, michael));
try (Transaction tx = db.beginTx()) {
db.execute("UNWIND {props} AS map CREATE (n) SET n = map", params);
tx.success();
}
Im using an unwind query in neo4j, with a nodejs driver (https://github.com/philippkueng/node-neo4j)
What I am trying to do is include an array of objects in the unwind query.
It currently works if I hard code the string as shown below, but i'm trying to have the array inserted dynamically.
UNWIND [{Label:'User',Lang:'English'},{Label:'Usuario',Lang:'Español'},{Label:'用户',Lang:'中文_简体'}] as ll
Regardless of the query I use, after testing, the above works, but if I do something like the following it doesn't:
var MyList = [{Label:'User',Lang:'English'},{Label:'Usuario',Lang:'Español'},{Label:'用户',Lang:'中文_简体'}];
"UNWIND "+ MyList " + as ll"
The problem is that when you do "UNWIND " + MyList you convert MyList to string, and it will be something like [object Object],[object Object],.... My first idea was to use JSON.stringify but that produces a JSON, which is not ok in cypher syntax (it is { "Label": ... } instead of { Label: ... }). The solution is to use parameters:
var queryString = 'UNWIND {list} as ll // continue query';
var queryParams = { list: MyList };
db.cypherQuery(queryString, queryParams, function(err, res) {
// handle response
});
Ideally you would use the ll identifier in your query.
However by seeing you have a property named Label, I remind you that currently it is not possible to add labels dynamically.
A possible query you might do is :
UNWIND MyList AS ll
CREATE (user:User) SET user.lang = {ll}.Lang
Chris
This question already has answers here:
How to Update Multiple Array Elements in mongodb
(16 answers)
Closed 5 years ago.
I recently started using MongoDB and I have a question regarding updating arrays in a document.
I got structure like this:
{
"_id" : ObjectId(),
"post" : "",
"comments" : [
{
"user" : "test",
"avatar" : "/static/avatars/asd.jpg",
"text" : "....."
}
{
"user" : "test",
"avatar" : "/static/avatars/asd.jpg",
"text" : "....."
}
{
"user" : "test",
"avatar" : "/static/avatars/asd.jpg",
"text" : "....."
}
...
]
}
I'm trying to execute the following query:
update({"comments.user":"test"},{$set:{"comments.$.avatar": "new_avatar.jpg"}},false,true)
The problem is that it update all documents, but it update only the first array element in every document. Is there any way to update all array elements or I should try to do it manually?
Thanks.
You cannot modify multiple array elements in a single update operation. Thus, you'll have to repeat the update in order to migrate documents which need multiple array elements to be modified. You can do this by iterating through each document in the collection, repeatedly applying an update with $elemMatch until the document has all of its relevant comments replaced, e.g.:
db.collection.find().forEach( function(doc) {
do {
db.collection.update({_id: doc._id,
comments:{$elemMatch:{user:"test",
avatar:{$ne:"new_avatar.jpg"}}}},
{$set:{"comments.$.avatar":"new_avatar.jpg"}});
} while (db.getPrevError().n != 0);
})
Note that if efficiency of this operation is a requirement for your application, you should normalize your schema such that the location of the user's avatar is stored in a single document, rather than in every comment.
One solution could be creating a function to be used with a forEach and evaling it (so it runs quickly). Assuming your collection is "article", you could run the following:
var runUpdate = function(){
db.article.find({"comments.user":"test").forEach( function(article) {
for(var i in article.comments){
article.comments[i].avatar = 'new_avatar.jpg';
}
db.article.save(article);
});
};
db.eval(runUpdate);
If you know the indexes you want to update you can do this with no problems like this:
var update = { $set: {} };
for (var i = 0; i < indexesToUpdate.length; ++i) {
update.$set[`comments.${indexesToUpdate[i]}. avatar`] = "new_avatar.jpg";
}
Comments.update({ "comments.user":"test" }, update, function(error) {
// ...
});
be aware that must of the IDE's will not accept the syntax but you can ignore it.
It seems like you can do this:
db.yourCollection.update({"comments.user":"test"},{$set:{"comments.0.avatar": "new_avatar.jpg", "comments.1.avatar": "new_avatar.jpg", etc...})
So if you have a small known number of array elements, this might be a little easier to do. If you want something like "comments.*.avatar" - not sure how to do that. It is probably not that good that you have so much data duplication tho..
I am trying to get a path from a base node to its root node as 1 row. The Cypher query looks like this:
start n = node:node_auto_index(Name = "user1") match path = (n-[r:IS_MEMBER_OF_GROUP*]->b) return last(collect(distinct path));
But when changing this over to the Neo4JClient syntax:
var k = clientConnection.Cypher
.Start(new { n = "node:node_auto_index(Name = 'user1')" })
.Match("path = (n-[r:IS_MEMBER_OF_GROUP*]->b)")
.ReturnDistinct<Node<Principles>>("last(collect(path))").Results;
It gets an error:
{"Value cannot be null.\r\nParameter name: uriString"}
When continuing on from there:
Neo4jClient encountered an exception while deserializing the response from the server. This is likely a bug in Neo4jClient.
Please open an issue at https://bitbucket.org/Readify/neo4jclient/issues/new
To get a reply, and track your issue, ensure you are logged in on BitBucket before submitting.
Include the full text of this exception, including this message, the stack trace, and all of the inner exception details.
Include the full type definition of Neo4jClient.Node`1[[IQS_Neo4j_TestGraph.Nodes.Principles, IQS Neo4j TestGraph, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]].
Include this raw JSON, with any sensitive values replaced with non-sensitive equivalents:
{
"columns" : [ "last(collect(path))" ],
"data" : [ [ {
"start" : "http://localhost:7474/db/data/node/3907",
"nodes" : [ "http://localhost:7474/db/data/node/3907", "http://localhost:7474/db/data/node/3906", "http://localhost:7474/db/data/node/3905", "http://localhost:7474/db/data/node/3904" ],
"length" : 3,
"relationships" : [ "http://localhost:7474/db/data/relationship/4761", "http://localhost:7474/db/data/relationship/4762", "http://localhost:7474/db/data/relationship/4763" ],
"end" : "http://localhost:7474/db/data/node/3904"
} ] ]
}
How would one convert the cypher query to Neo4JClient query?
Well, the thing you are returning is a PathsResult not a Node<>, so if you change your query to be:
var k = clientConnection.Cypher
.Start(new { n = "node:node_auto_index(Name = 'user1')" })
.Match("path = (n-[r:IS_MEMBER_OF_GROUP*]->b)")
.ReturnDistinct<PathsResult>("last(collect(path))").Results; //<-- Change here
you will get results, this returns what I get from running your query against my db, if you specifically want the nodes this post: Getting PathsResults covers converting to actual nodes and relationships.
One other thing, (and this will help the query perform better as neo4j can cache the execution plans easier), is that you can change your start to make it use parameters by doing:
.Start(new { n = Node.ByIndexLookup("node_auto_index", "Name", "user1")})