How do I create and update nodes and property using plain cypher query?
Below is my query:
MERGE (c:contact {guid : '500010'})
ON CREATE SET
c.data_source = '1',
c.guid = '500010',
c.created = timestamp()
ON MATCH SET
c.lastUpdated = timestamp()
MERGE (s:speciality {specialtygroup_desc : 'cold'})
ON CREATE SET s.data_source = '1',
s.specialtygroup_desc = 'fever',
s.created = timestamp()
ON MATCH SET s.data_source = '1',
s.specialtygroup_desc = 'comman cold',
s.lastUpdated = timestamp()
MERGE (c)-[r:is_specialised_in]->(s)
ON CREATE SET
r.duration = 1
ON MATCH SET
r.duration = r.duration + 1
On the first run, node is created as "fever".
On the second run, I have updated the specialty_group to "common cold". But it is creating new node with "fever". I am not able to update the "fever" to "common cold".
What changes should I make to the above query?
The MERGE (s:speciality {specialtygroup_desc : 'cold'}) clause looks for a specialtygroup_desc value of "cold".
During the first execution, that MERGE clause finds no "cold" node -- so it creates one, and the subsequent ON CREATE clause changes it to "fever".
During the second execution, that MERGE again finds no "cold" node (since it is now a "fever" node), so it again creates a "cold" node and the ON CREATE clause yet again changes it to "fever". The ON MATCH clause is never used. This is why you end up with another "fever" node.
Unfortunately, you have not explained your use case in enough detail to offer a recommendation for how to fix your code.
I think you want to update all node "cold" to "common cold" and if not exists "cold" or "common cold", create new "fever" ?
My suggestion:
OPTIONAL MATCH (ss:speciality {specialtygroup_desc : 'cold'}
SET ss.specialtygroup_desc='common cold', ss.lastUpdated = timestamp()
MERGE (c:contact {guid : '500010'})
ON CREATE SET
c.data_source = '1',
c.guid = '500010',
c.created = timestamp()
ON MATCH SET
c.lastUpdated = timestamp()
MERGE (s:speciality {specialtygroup_desc : 'common cold'})
ON CREATE SET s.data_source = '1',
s.specialtygroup_desc = 'fever',
s.created = timestamp()
MERGE (c)-[r:is_specialised_in]->(s)
ON CREATE SET
r.duration = 1
ON MATCH SET
r.duration = r.duration + 1
Related
MERGE (c:contact {guid : '500010'})
ON CREATE SET
c.data_source = '1',
c.guid = '500010',
c.created = timestamp()
ON MATCH SET
c.lastUpdated = timestamp()
MERGE (s:speciality {specialtygroup_desc : 'cold'})
ON CREATE SET s.data_source = '1',
s.specialtygroup_desc = 'fever',
s.created = timestamp()
ON MATCH SET s.data_source = '1',
s.specialtygroup_desc = 'comman cold',
s.lastUpdated = timestamp()
MERGE (c)-[r:is_specialised_in]->(s)
ON CREATE SET
r.duration = 1
ON MATCH SET
r.duration = r.duration + 1
On the first run, node is created as "fever". On the second run, I have updated the specialty_group to "common cold". But it is creating new node with "fever". I am not able to update the "fever" to "common cold". What changes should I make to the above query?
I have edges like this:
(People)-[:USE]->(Product)
(People)-[:REVIEW]->(Product)
Now I have a new csv of People who are reviewers but they are missing some of the attributes I have already.
I want to do something like:
LOAD CSV WITH HEADERS FROM "file:///abcd.csv" AS row
MERGE (svc:Consumer {name: row.referring_name})
ON CREATE SET
svc.skewNum = toInteger(row.skew_num)
MERGE (p:PrimaryConsumer) WHERE p.name = svc.name
ON MATCH SET
svc.city = p.city,
svc.latitude = toFloat(p.latitude),
svc.longitude = toFloat(p.longitude),
svc.consumerId = toInteger(p.primaryConsumerId)
Which borks:
Neo.ClientError.Statement.SyntaxError: Invalid input 'H': expected 'i/I' (line 10, column 28 (offset: 346))
"MERGE (p:PrimaryConsumer) WHERE p.name = svc.name"
I am 100% assured that the names are unique and will match a unique consumer name in the existing set of nodes (to be seen).
How would I add existing attributes to new data when I have a match on unique node attributes? (I am hoping to get unique id's, but I have to be able to perform an update to the new data on match)
Thank you.
This is the entire cypher script -- modified as per #cypher's input.
USING PERIODIC COMMIT
LOAD CSV WITH HEADERS FROM "file:///abcde.csv" AS row
MERGE (svc:Consumer {name: row.referring_name})
ON CREATE SET
svc.skeyNum = toInteger(row.skew_num)
MATCH (p:primaryConsumer {name: svc:name})
ON MATCH SET
svc.city = p.city,
svc.latitude = toFloat(p.latitude),
svc.longitude = toFloat(p.longitude),
svc.providerId = toInteger(p.providerId)
MERGE (spec:Product {name: row.svc_prod_name})
ON CREATE SET
spec.name = row.svc_prov_name,
spec.skew = toInteger(row.skew_id),
spec.city = row.svc_prov_city,
spec.totalAllowed = toFloat(row.total_allowed)
MERGE (svc)-[r:CONFIRMED_PURCHASE]->(spec)
ON MATCH SET r.totalAllowed = r.totalAllowed + spec.totalAllowed
ON CREATE SET r.totalAllowed = spec.totalAllowed
;
MERGE does not accept a WHERE clause.
Change this:
MERGE (p:PrimaryConsumer) WHERE p.name = svc.name
to this:
MERGE (p:PrimaryConsumer {name: svc.name})
[EDIT]
You entire query should then look like this:
LOAD CSV WITH HEADERS FROM "file:///abcd.csv" AS row
MERGE (svc:Consumer {name: row.referring_name})
ON CREATE SET
svc.skewNum = toInteger(row.skew_num)
MERGE (p:PrimaryConsumer {name: svc.name})
ON MATCH SET
svc.city = p.city,
svc.latitude = toFloat(p.latitude),
svc.longitude = toFloat(p.longitude),
svc.consumerId = toInteger(p.primaryConsumerId)
I am trying to make a Cypher query which makes 2 nodes and adds a relationship between them.
For adding a node I'm checking if the node is existing or not, if existing then I'm simply going ahead and setting a property.
// Query 1 for creating or updating node 1
MERGE (Kunal:PERSON)
ON CREATE SET
Kunal.name = 'Kunal',
Kunal.type = 'Person',
Kunal.created = timestamp()
ON MATCH SET
Kunal.lastUpdated = timestamp()
RETURN Kunal
// Query 2 for creating or updating node 2
MERGE (Bangalore: LOC)
ON CREATE SET
Bangalore.name = 'Bangalore',
Bangalore.type = 'Location',
Bangalore.created = timestamp()
ON MATCH SET
Bangalore.lastUpdated = timestamp()
RETURN Bangalore
Likewise I am checking if a relationship exists between the above created nodes, if not exists then creating it else updating its properties.
// Query 3 for creating relation or updating it.
MERGE (Kunal: PERSON { name: 'Kunal', type: 'Person' })
MERGE (Bangalore: LOC { name: 'Bangalore', type: 'Location' })
MERGE (Kunal)-[r:LIVES_IN]->(Bangalore)
ON CREATE SET
r.duration = 36
ON MATCH SET
r.duration = r.duration + 1
RETURN *
The problem is these are 3 separate queries which will have 3 database calls when I run it via the Python driver. Is there a way to optimize these queries into a single query.
Of course you can concatenate your three queries to one.
In this case you can omit the first and second MERGE of your last query, because it is assured by the start of new query already.
MERGE (kunal:PERSON {name: ‘Kunal'})
ON CREATE SET
kunal.type = 'Person',
kunal.created = timestamp()
ON MATCH SET
kunal.lastUpdated = timestamp()
MERGE (bangalore:LOC {name: 'Bangalore'})
ON CREATE SET
bangalore.type = 'Location',
bangalore.created = timestamp()
ON MATCH SET
bangalore.lastUpdated = timestamp()
MERGE (kunal)-[r:LIVES_IN]->(bangalore)
ON CREATE SET
r.duration = 36
ON MATCH SET
r.duration = r.duration + 1
RETURN *
I am creating multiple relationships in one query. If a match is not found for the first relationship the second one is not created. If both matches exist then both relationships work.
Example:
Assume that 'MATCH1ID' below does not exist but 'MATCH2ID' does. Why does this happen?
DOES NOT WORK
MERGE (NewRecord:OBJECTNAME { Id: 'ABZDEFG' })
SET NewRecord.name='NEWNAME'
WITH NewRecord
MATCH (a)
WHERE a.Id = 'MATCH1ID'
CREATE (a)-[ar:Relationship1]->(NewRecord)
WITH NewRecord MATCH (b)
WHERE b.Id = 'MATCH2ID'
CREATE (b)-[br:Relationship2]->(NewRecord)
(If I switch the order of the node that does exist to be first in the order it works)
WORKS
MERGE (NewRecord:OBJECTNAME { Id: 'ABZDEFG' })
SET NewRecord.name='NEWNAME'
WITH NewRecord
MATCH (b)
WHERE b.Id = 'MATCH2ID'
CREATE (b)-[br:Relationship2]->(NewRecord)
WITH NewRecord
MATCH (a)
WHERE a.Id = 'MATCH1ID'
CREATE (a)-[ar:Relationship1]->(NewRecord)
You can try using a OPTIONAL MATCH instead of a simple MATCH:
MERGE (NewRecord:OBJECTNAME { Id: 'ABZDEFG' })
SET NewRecord.name='NEWNAME'
WITH NewRecord
OPTIONAL MATCH (a)
WHERE a.Id = 'MATCH1ID'
FOREACH(x IN (CASE WHEN a IS NULL THEN [] ELSE [1] END) |
CREATE (a)-[ar:Relationship1]->(NewRecord)
)
WITH NewRecord
OPTIONAL MATCH (b)
WHERE b.Id = 'MATCH2ID'
FOREACH(x IN (CASE WHEN b IS NULL THEN [] ELSE [1] END) |
CREATE (b)-[br:Relationship2]->(NewRecord)
)
Also, this query uses a trick with FORACH and CASE WHEN to handle conditions. In this case, the CREATE statement is executed only when a or b variables are not null.
See Neo4j: LOAD CSV - Handling Conditionals.
I have 2 csv files and their sructure is as follows:
1.csv
id name age
1 aa 23
2 bb 24
2.csv
id product location
1 apple CA
2 samsung PA
1 HTC AR
2 philips CA
3 sony AR
// 1.csv
LOAD CSV WITH HEADERS FROM "file:///G:/1.csv" AS csvLine
CREATE (a:first { id: toInt(csvLine.id), name: csvLine.name, age: csvLine.age})
// 2.csv
LOAD CSV WITH HEADERS FROM "file:///G:/2.csv" AS csvLine
CREATE (b:second { id: toInt(csvLine.id), product: csvLine.product, location: csvLine.location})
Now i want to create another node called "third", using the following cypher query.
LOAD CSV WITH HEADERS FROM "file:///G:/1.csv" AS csvLine
MATCH c = (a:first), d = (b.second)
FOREACH (n IN nodes(c) |
CREATE (e:third)
SET e.name = label(a) + label(b) + "id"
SET e.origin = label(a)
SET e.destination = label(b)
SET e.param = a.id)
But the above query give me duplicate entries. I think here it runs 2 time after the load. Please suggest or any alternative way for this.
CREATE always creates, even if something is already there. So that's why you're getting duplicates. You probably want MERGE which only creates an item if it doesn't already exist.
I wouldn't ever do CREATE (e:third) or MERGE (e:third) because without specifying properties, you'll end up with duplicates anyway. I'd change this:
CREATE (e:third)
SET e.name = label(a) + label(b) + "id"
SET e.origin = label(a)
SET e.destination = label(b)
SET e.param = a.id)
To this:
MERGE (e:third { name: label(a) + label(b) + "id",
origin: label(a),
destination: label(b),
param: a.id })
This then would create the same node when necessary, but avoid creating duplicates with all the same property values.
Here's the documentation on MERGE
You don't use csvLine at all for matching the :first and :second node!
So your query doesn't make sense
This doesn't make sense either:
MATCH c = (a:first), d = (b.second)
FOREACH (n IN nodes(c) |
CREATE (e:third)
c are paths with a single node, i.e. (a)
so instead of the foreach you would use a directly instead