I have a Neo4j database containing information on Congressmen. The problem I'm having is if there is a vacant position. When this happens I am using the same key:value in the "Congressmen" index. I tried the code below because in the py2neo documentation it states that the add function is idempotent
#Check if we have any vacancies and if so if they match the one that we currently want to add
query="start n=node:Congressmen('website:N/A') return n"
result= cypher.execute(graph_db, query.encode('utf-8', errors='ignore'))
#Match what we already have
if str(result[0]) != "[]":
#create is idempotent so will only create a new node if properties are different
rep, = graph_db.create({"name" : userName, "website" : web, "district" : int(district), "state" : child[2].text, "party" : child[4].text, "office" : child[5].text, "phone" : child[6].text, "house" : "House of Representatives"})
cong = graph_db.get_or_create_index(neo4j.Node, "Congressmen")
# add the node to the index
cong.add("website", web, rep)
When I checked the interface after running the code 3 times I have duplicate nodes.
Is it possible to prevent the nodes from duplicating and still be able to index them using the same key/value?
The Index.add method is certainly idempotent: the same entity can only be added once to a particular entry point. The GraphDatabaseService.create method is not however. Each time you run the create method, a new node is created and each run of add appends that new node to the index. You probably want to use the Index.add_if_none, Index.create_if_none or Index.get_or_create method instead.
Related
I have the following paramObj and dbQuery
paramObj = {
email: newUser.email,
mobilenumber: newUser.telephone,
password: newUser.password,
category: newUser.category,
name: newUser.name,
confirmuid: verificationHash,
confirmexpire: expiryDate.valueOf(),
rewardPoints: 0,
emailconfirmed: 'false',
paramVehicles: makeVehicleArray,
paramVehicleProps: vehiclePropsArray
}
dbQuery = `CREATE (user:Person:Owner {email:$email})
SET user += apoc.map.clean(paramObj,
['email','paramVehicles','paramVehiclesProps'],[])
WITH user, $paramVehicles AS vehicles
UNWIND vehicles AS vehicle
MATCH(v:Vehicles {name:vehicle})
CREATE UNIQUE (user)-[r:OWNS {since: timestamp()}]->(v)
RETURN user,r,v`;
Then I tried to execute
commons.session
.run(dbQuery, paramObj)
.then(newUser => {
commons.session.close();
if (!newUser.records[0]) {........
I am getting
Error: {"code":"Neo.ClientError.Statement.SyntaxError","name":"Neo4jError"}
which doesn't direct me anywhere. Can anyone tell me what am I doing wrong here?
This is actually the first time I am using the query format .run(dbQuery, paramObj) but this format is critical to my use case. I am using Neo4j 3.4.5 community with apoc plugin installed.
Ok...so I followed #inversFalcon suggestion to test in browser and came up with following parameters and query that closely match the ones above:
:params paramObj:[{ email:"xyz123#abc.com", mobilenumber:"8711231234",password:"password1", category:"Owner",name:"Michaell",vehicles:["Toyota","BMW","Nissan"],vehicleProps: [] }]
and query
PROFILE
CREATE (user:Person:Owner {email:$email})
SET user += apoc.map.clean($paramObj, ["email","vehicles","vehicleProps"],[])
WITH user, $vehicles AS vehicles
UNWIND vehicles AS vehicle
MATCH(v:Vehicles {name:vehicle})
MERGE (user)-[r:OWNS {since: timestamp()}]->(v)
RETURN user,r,v;
Now I get
Neo.ClientError.Statement.TypeError: Can't coerce `List{Map{name -> String("Michaell"), vehicles -> List{String("Toyota"), String("BMW"), String("Nissan")},.......
I also reverted to neo4j 3.2 (re: an earlier post by Mark Needham) and got the same error.
You should try doing an EXPLAIN of the query using the browser to troubleshoot it.
A few of the things I'm seeing here:
You're referring to paramObj, but it's not a parameter (rather, it's the map of parameters you're passing in, but it itself is not a parameter you can reference in the query). If you need to reference the entire set of parameters being passed in, then you need to use nested maps, and have paramObj be a key in the map that you pass as the parameter map (and when you do use it in the query, you'll need to use $paramObj)
CREATE UNIQUE is deprecated, you should use MERGE instead, though be aware that it does behave in a different manner (see the MERGE documentation as well as our knowledge base article explaining some of the easy-to-miss details of how MERGE works).
I am not sure what caused the coercion error to disappear but it did with the same query and I got a "expected parameter error" this was fixed by using $paramObj.email, etc. so the final query looks like this:
CREATE (user:Person:Owner {email: $paramObj.email})
SET user += apoc.map.clean($queryObj, ["email","vehicles","vehicleProps"],[])
WITH user, $paramObj.vehicles AS vehicles
UNWIND vehicles AS vehicle
MATCH(v:Vehicles {name:vehicle})
MERGE (user)-[r:OWNS {since: timestamp()}]->(v)
RETURN user,r,v;
which fixed my original problem of how to remove properties from a map when using SET += map.
Create (sub:Subscription {name:"Paul",mobile:"8763xxxxx",email:"info#aliant.com"}),
Create (sub:Subscription {name:"Peter",mobile:"87638xxxxx",email:"info#aliant.com"}),
Create (sub:Subscription {name:"James",mobile:"87638xxxxx",email:"info#aliant.com"}),
Create (sub:Subscription {name:"Bill",mobile:"87638xxxxx",email:"info#aliant.com"})
Return sub;
I am very new to Neo4j/Cypher.....Why do I get an "unexpected "C" error on the second Create. I am using 2.3.2 community edition. The manual says this should would work...I also tried the parameter example section 12.1 in the manual it doesn't work either.
The commas are illegal - this form works:
Create (sub1:Subscription {name:"Paul",mobile:"8763xxxxx",email:"info#aliant.com"})
Create (sub2:Subscription {name:"Peter",mobile:"87638xxxxx",email:"info#aliant.com"})
Create (sub3:Subscription {name:"James",mobile:"87638xxxxx",email:"info#aliant.com"})
Create (sub4:Subscription {name:"Bill",mobile:"87638xxxxx",email:"info#aliant.com"})
Return sub1, sub2, sub3, sub4
If the you don't need a value back, then this will just create the nodes:
Create (:Subscription {name:"Paul",mobile:"8763xxxxx",email:"info#aliant.com"})
Create (:Subscription {name:"Peter",mobile:"87638xxxxx",email:"info#aliant.com"})
Create (:Subscription {name:"James",mobile:"87638xxxxx",email:"info#aliant.com"})
Create (:Subscription {name:"Bill",mobile:"87638xxxxx",email:"info#aliant.com"})
Try this:
UNWIND [{name:"Paul",mobile:"8763xxxxx",email:"info#aliant.com"}, {name:"Peter",mobile:"87638xxxxx",email:"info#aliant.com"}] as subscriptions
CREATE (sub:Subscription)
SET sub=subscriptions
Or this:
[Note: This syntax is deprecated in Neo4j version 2.3. It may be removed in a future major release. See the above code using UNWIND for how to achieve the same functionality.
]:
{
"subscriptions" : [ {
"name" : "A",
"email" : "a#b.c"
}, {
"name" : "B",
"email" : "x#y.z"
} ]
}
Create (sub:Subscription: {subscriptions}) Return sub
See, if that helps, or Refer this link.
I have a question about the query based on the predefined constraints in PopotoJs. In this example, the graph can be filtered based on the constraints defined in the search boxes. The sample file in this example visualizations folder, constraint is only defined for "Person" node. It is specified in the sample html file like the following:
"Person": {
"returnAttributes": ["name", "born"],
"constraintAttribute": "name",
// Return a predefined constraint that can be edited in the page.
"getPredefinedConstraints": function (node) {
return personPredefinedConstraints;
},
....
In my graph I would like to apply that query function for more than one node. For example I have 2 nodes: Contact (has "name" attribute) and Delivery (has "address" attribute)
I succeeded it by defining two functions for each nodes. However, I also had to put two search box forms with different input id (like constraint1 and constraint2). And I had to make the queries in the associated search boxes.
Is there a way to make queries which are defined for multiple nodes in one search box? For example searching Contact-name and/or Delivery-adress in the same search box?
Thanks
First I’d like to specify that the predefined constraints feature is still experimental (but fully functional) and doesn’t have any documentation yet.
It is intended to be used in configuration to filter data displayed in nodes and in the example the use of search boxes is just to show dynamically how it works.
A common use of this feature would be to add the list of predefined constraint you want in the configuration for every node types.
Let's take an example:
With the following configuration example the graph will be filtered to show only Person nodes having "born" attribute and only Movie nodes with title in the provided list:
"Person": {
"getPredefinedConstraints": function (node) {
return ["has($identifier.born)"];
},
...
}
"Movie": {
"getPredefinedConstraints": function (node) {
return ["$identifier.title IN [\"The Matrix\", \"The Matrix Reloaded\", \"The Matrix Revolutions\"]"];
},
...
}
The $identifier variable is then replaced during query generation with the corresponding node identifier. In this case the generated query would look like this:
MATCH (person:`Person`) WHERE has(person.born) RETURN person
In your case if I understood your question correctly you are trying to use this feature to implement a search box to filter the data. I'm still working on that feature but it won't be available soon :(
This is a workaround but maybe it could work in your use case, you could keep the search box value in a variable:
var value = d3.select("#constraint")[0][0].value;
inputValue = value;
Then use it in the predefined constraint of all the nodes type you want.
In this example Person will be filtered based on the name attribute and Movie on title:
"Person": {
"getPredefinedConstraints": function (node) {
if (inputValue) {
return ["$identifier.name =~ '(?i).*" + inputValue + ".*'"];
} else {
return [];
}
},
...
}
"Movie": {
"getPredefinedConstraints": function (node) {
if (inputValue) {
return ["$identifier.title =~ '(?i).*" + inputValue + ".*'"];
} else {
return [];
}
},
...
}
Everything is in the HTML page of this example so you can view the full source directly on the page.
#Popoto, thanks for the descriptive reply. I tried your suggestion and it worked pretty much well. With the actual codes, when I make a query it was showing only the queried node and make the other node amount zero. I wanted to make a query which queries only the related node while the number of other nodes are still same.
I tried a temporary solution for my problem. What I did is:
Export the all the node data to JSON file, search my query constraint in the exported JSONs, if the file is existing in JSON, then run the query in the related node; and if not, do nothing.
With that way, of course I needed to define many functions with different variable names (as much as the node amount). Anyhow, it is not a propoer way, bu it worked for now.
I created the following nodes and relationship in neo4j
CREATE (United_States:Citizenship { type : “Naturalized”})
CREATE (United_States:Citizenship { type : “Native_Born”})
CREATE (uid:Person { unique_id: 'A23AF39D-BEED-4FFC-B080-1362920FA7A8', id_type: '128bit_UUID' })
MATCH (uid:Person),(Native_Born:Citizenship) WHERE uid:Person="A23AF39D-BEED-4FFC-B080-1362920FA7A8" CREATE (uid) <- [ r:PersonUniqueIdentifier ] -> (Native_Born)
CREATE (fn:Person { first_name:'Willie', id_type:'128bit_UUID'})
CREATE (ln:Person { last_name:'Armstrong', id_type:'128bit_UUID'}))
CREATE CONSTRAINT ON (uid:Person) ASSERT Person.unique_id IS UNIQUE
CREATE INDEX ON :Person(unique_id)
I do not see the 'PersonUniqueIdentifier' Relation between the Citizenship node and id:Person node on the graph.
Screen shot of graph
Firstly, I would make a habit of doing the indexes/constraints first. There's not a lot of data here, but if you add an index after adding the data, it will need to go through all your nodes first. Also, creating a constraint also adds an index for you, so no need for that line. It seems like you're mixing up variables here, so refactoring a bit:
CREATE CONSTRAINT ON (person:Person) ASSERT person.unique_id IS UNIQUE
Also your Citizenship CREATEs are using the same variable name. I don't know if that would necessarily cause a problem, but it's simpler to do this anyway:
CREATE (:Citizenship { type : “Naturalized”}), (:Citizenship { type : “Native_Born”})
This statement looks fine to me (though, again, you could lose the variable if you wanted to):
CREATE (person:Person { unique_id: 'A23AF39D-BEED-4FFC-B080-1362920FA7A8', id_type: '128bit_UUID' })
Here there are a few problems. Here's how I would refactor it:
MATCH (person:Person),(citizenship:Citizenship)
WHERE
person.unique_id="A23AF39D-BEED-4FFC-B080-1362920FA7A8",
citizenship.type = 'Native_Born'
CREATE (person)-[:HAS_CITIZENSHIP]->(citizenship)
I'm not really sure what you want to do here. It seems like you want to create one person, so I would do this:
CREATE (:Person { first_name:'Willie', id_type: '128bit_UUID', last_name:'Armstrong'})
in our data model we have externalized some of our domain entities values into external nodes. The model for a service object looks like:
ref=node(0),
ref<-[:SERVICE]-subRefNode<-[:SERVICE]-aService-[:HAS_PROPERTY_VALUE]->propValueNode-[:IS_OF_TYPE]->propDefType,
ref<-[:SERVICE]-subRefNode-[:HAS_PROPERTY]->propDefType
The node subRefNode holds a relationship to all services. All possible properties for a service are defined through ref<-[:SERVICE]-subRefNode-[:HAS_PROPERTY]->propDefType. So it could be that a certain node doesn't have a propValueNode yet for a certain property (e.g. a comment) and others might have one but its empty (the user might have entered a comment and then cleared it).
So my question is how do I get the nodes with an empty propValueNode.value and also the ones that do not have a propertyValueNode yet? I thought about something like...
START ref=node(0) MATCH ref<-[:SERVICE]-subRef, aService-[pvRel?:HAS_PROPERTY_VALUE]->propValueNode-[pdRel:IS_OF_TYPE]->propDef<-[:HAS_PROPERTY]-subRef<-[:SERVICE]-aService WHERE (pvRel IS NOT NULL AND propDef.name = 'comment' AND propValueNode.value=~"^$") OR (pvRel IS NULL AND pdRel IS NULL AND propDef.name="comment") RETURN DISTINCT aService.debug
http://console.neo4j.org/r/7zeoay
...but this misses the ones without a propValueNode. Any hints are appreciated!
Regards,
Andi
If http://console.neo4j.org/r/7zeoay is not valid anymore, here's the initial graph setup:
start _0 = node(0) with _0
create
(_1 {type:"SubReferenceNode", name:"SubRef"}),
(_2 {type:"Service", debug:"S0 empty value"}),
(_3 {type:"Service", debug:"S1 missing value node"}),
(_4 {type:"Service", debug:"S2 with value"}),
(_5 {type:"PropertyDefintion", name:"comment"}),
(_6 {type:"PropertyDefintion", name:"name"}),
(_7 {type:"PropertyValue", value:"S0 empty value"}),
(_8 {type:"PropertyValue", value:"S1 missing value node"}),
(_9 {type:"PropertyValue", value:"S2 with value"}),
(_10 {type:"PropertyValue", value:""}),
(_11 {type:"PropertyValue", value:"This is a comment"}),
_0<-[:SERVICE]-_1,
_1<-[:SERVICE]-_2,
_1<-[:SERVICE]-_3,
_1<-[:SERVICE]-_4,
_1-[:HAS_PROPERTY]->_5,
_1-[:HAS_PROPERTY]->_6,
_2-[:HAS_PROPERTY_VALUE]->_7,
_7-[:IS_OF_TYPE]->_6,
_3-[:HAS_PROPERTY_VALUE]->_8,
_8-[:IS_OF_TYPE]->_6,
_4-[:HAS_PROPERTY_VALUE]->_9,
_9-[:IS_OF_TYPE]->_6,
_2-[:HAS_PROPERTY_VALUE]->_10,
_10-[:IS_OF_TYPE]->_5,
_4-[:HAS_PROPERTY_VALUE]->_11,
_11-[:IS_OF_TYPE]->_5
You can combine two queries, one is to return the service which has an empty value for the property "comment", and another returns the service which does not have a propery value that is of the type "comment", in other word, none of the service property values is of the the type "comment".
START ref=node(0)
MATCH ref<-[:SERVICE]-subRef, aService-[pvRel?:HAS_PROPERTY_VALUE]->propValueNode-[pdRel:IS_OF_TYPE]->propDef<-[:HAS_PROPERTY]-subRef<-[:SERVICE]-aService
WHERE (pvRel IS NOT NULL AND propDef.name = 'comment' AND propValueNode.value=~"^$")
RETURN DISTINCT aService.debug
UNION
START ref=node(0)
MATCH ref<-[:SERVICE]-subRef, aService-[pvRel:HAS_PROPERTY_VALUE]->propValueNode-[pdRel:IS_OF_TYPE]->propDef<-[:HAS_PROPERTY]-subRef<-[:SERVICE]-aService
with aService, collect(propDef.name) as propNames
WHERE NONE( propName in propNames where propName = 'comment')
RETURN DISTINCT aService.debug
The alternative solution without using the "UNION" clause is to get all value nodes for each service and returns only those service that either none of its values is of type "comment" or there is one value of the type "comment" and the value is empty, as shown in the "Where" clause below,
START ref=node(0)
MATCH ref<-[:SERVICE]-subRef, aService-[pvRel:HAS_PROPERTY_VALUE]->propValueNode-[pdRel?:IS_OF_TYPE]->propDef<-[:HAS_PROPERTY]-subRef<-[:SERVICE]-aService
WHERE propDef.name = 'comment'
WITH aService, collect(propValueNode) AS valueNodes, propDef
WHERE NONE (v IN valueNodes
WHERE v-[:IS_OF_TYPE]->propDef) OR SINGLE (v IN valueNodes
WHERE v.value=~"^$" AND v-[:IS_OF_TYPE]->propDef)
RETURN aService.debug