I am new to Neo4j and graph database. While trying to import a few relationships from a CSV file, I can see that there are no records, even when the file is filled with enough data.
LOAD CSV with headers FROM 'file:/graphdata.csv' as row WITH row
WHERE row.pName is NOT NULL
MERGE(transId:TransactionId)
MERGE(refId:RefNo)
MERGE(kewd:Keyword)
MERGE(accNo:AccountNumber {bName:row.Bank_Name, pAmt:row.Amount, pName:row.Name})
Followed by:
LOAD CSV with headers FROM 'file/graphdata.csv' as row WITH row
WHERE row.pName is NOT NULL
MATCH(transId:TransactionId)
MATCH(refId:RefNo)
MATCH(kewd:Keyword)
MATCH(accNo:AccountNumber {bName:row.Bank_Name, pAmt:row.Amount, pName:row.Name})
MERGE(transId)-[:REFERENCE]->(refId)-[:USED_FOR]->(kewd)-[:AGAINST]->(accNo)
RETURN *
Edit (table replica):
TransactionId Bank_Name RefNo Keyword Amount AccountNumber AccountName
12345 ABC 78 X 1000 5421 WE
23456 DEF X 2000 5471
34567 ABC 32 Y 3000 4759 HE
Is it likely the case that the Nodes and relationships are not created at all? How do I get all these desired relationships?
Neither file:/graphdata.csv nor file/graphdata.csv are legal URLs. You should use file:///graphdata.csv instead.
By default, LOAD CSV expects a "csv" file to consist of comma separated values. You are instead using a variable number of spaces as a separator (and sometimes as a trailer). You need to either:
use a single space as the separator (and specify an appropriate FIELDTERMINATOR option). But this is not a good idea for your data, since some bank names will likely also contain spaces.
use a comma separator (or some other character that will not occur in your data).
For example, this file format would work better:
TransactionId,Bank_Name,RefNo,Keyword,Amount,AccountNumber,AccountName
12345,ABC,78,X,1000,5421,WE
23456,DEF,,X,2000,5471
34567,ABC,32,Y,3000,4759,HE
Your Cypher query is attempting to use row properties that do not exist (since the file has no corresponding column headers). For example, your file has no pName or Name headers.
Your usage of the MERGE clause is probably not doing what you want, generally. You should carefully read the documentation, and this answer may also be helpful.
Related
I have two files. First file contain list of users with certain properties. I have loaded them in Neo4j as below:
USING PERIODIC COMMIT LOAD CSV WITH HEADERS FROM "file:///users.csv" AS row
CREATE (U:User{userid:row.userid, username:row.username})
Now, I have a second file that contains pincodes of the places the user stays or ever stayed at. Example:
User Pincodes
A 001
B 002
A 003
I want to add a property to the label User such that it adds all the pincodes as a list. But when I am using the below query, it only stores the most latest value and not all the values as a list.
USING PERIODIC COMMIT 1000
LOAD CSV WITH HEADERS FROM "file:///user_pincode.csv" AS line
MATCH (U:User)
WHERE U.userid=line.userid
SET U.pincode=[line.pincode]
Any suggestions would be really helpful.
[UPDATED]
You can do this:
USING PERIODIC COMMIT 1000
LOAD CSV FROM "file:///user_pincode.csv" AS line
MATCH (u:User)
WHERE u.userid=line[0]
SET u.pincode = COALESCE(u.pincode, []) + line[1]
Since your CSV data has no header, this query omits the WITH HEADERS option, and treats line as an array. It appends the new pincode to the end of the existing pincode list (or, if the pincode property did not already exist, initialize that property with a single-element list). The COALESCE function returns the first argument that is non-NULL.
I can query using Cypher in Neo4j from the Panama database the countries of three types of identity holders (I define that term) namely Entities (companies), officers (shareholders) and Intermediaries (middle companies) as three attributes/columns. Each column has single or double entries separated by colon (eg: British Virgin Islands;Russia). We want to concatenate the countries in these columns into a unique set of countries and hence obtain the count of the number of countries as new attribute.
For this, I tried the following code from my understanding of Cypher:
MATCH (BEZ2:Officer)-[:SHAREHOLDER_OF]->(BEZ1:Entity),(BEZ3:Intermediary)-[:INTERMEDIARY_OF]->(BEZ1:Entity)
WHERE BEZ1.address CONTAINS "Belize" AND
NOT ((BEZ1.countries="Belize" AND BEZ2.countries="Belize" AND BEZ3.countries="Belize") OR
(BEZ1.status IN ["Inactivated", "Dissolved shelf company", "Dissolved", "Discontinued", "Struck / Defunct / Deregistered", "Dead"]))
SET BEZ4.countries= (BEZ1.countries+","+BEZ2.countries+","+BEZ3.countries)
RETURN BEZ3.countries AS IntermediaryCountries, BEZ3.name AS
Intermediaryname, BEZ2.countries AS OfficerCountries , BEZ2.name AS
Officername, BEZ1.countries as EntityCountries, BEZ1.name AS Companyname,
BEZ1.address AS CompanyAddress,DISTINCT count(BEZ4.countries) AS NoofConnections
The relevant part is the SET statement in the 7th line and the DISTINCT count in the last line. The code shows error which makes no sense to me: Invalid input 'u': expected 'n/N'. I guess it means to use COLLECT probably but we tried that as well and it shows the error vice-versa'd between 'u' and 'n'. Please help us obtain the output that we want, it makes our job hell lot easy. Thanks in advance!
EDIT: Considering I didn't define variable as suggested by #Cybersam, I tried the command CREATE as following but it shows the error "Invalid input 'R':" for the command RETURN. This is unfathomable for me. Help really needed, thank you.
CODE 2:
MATCH (BEZ2:Officer)-[:SHAREHOLDER_OF]->(BEZ1:Entity),(BEZ3:Intermediary)-
[:INTERMEDIARY_OF]->(BEZ1:Entity)
WHERE BEZ1.address CONTAINS "Belize" AND
NOT ((BEZ1.countries="Belize" AND BEZ2.countries="Belize" AND
BEZ3.countries="Belize") OR
(BEZ1.status IN ["Inactivated", "Dissolved shelf company", "Dissolved",
"Discontinued", "Struck / Defunct / Deregistered", "Dead"]))
CREATE (p:Connections{countries:
split((BEZ1.countries+";"+BEZ2.countries+";"+BEZ3.countries),";")
RETURN BEZ3.countries AS IntermediaryCountries, BEZ3.name AS
Intermediaryname, BEZ2.countries AS OfficerCountries , BEZ2.name AS
Officername, BEZ1.countries as EntityCountries, BEZ1.name AS Companyname,
BEZ1.address AS CompanyAddress, AS TOTAL, collect (DISTINCT
COUNT(p.countries)) AS NumberofConnections
Lines 8 and 9 are the ones new and to be in examination.
First Query
You never defined the identifier BEZ4, so you cannot set a property on it.
Second Query (which should have been posted in a separate question):
You have several typos and a syntax error.
This query should not get an error (but you will have to determine if it does what you want):
MATCH (BEZ2:Officer)-[:SHAREHOLDER_OF]->(BEZ1:Entity),(BEZ3:Intermediary)- [:INTERMEDIARY_OF]->(BEZ1:Entity)
WHERE BEZ1.address CONTAINS "Belize" AND NOT ((BEZ1.countries="Belize" AND BEZ2.countries="Belize" AND BEZ3.countries="Belize") OR (BEZ1.status IN ["Inactivated", "Dissolved shelf company", "Dissolved", "Discontinued", "Struck / Defunct / Deregistered", "Dead"]))
CREATE (p:Connections {countries: split((BEZ1.countries+";"+BEZ2.countries+";"+BEZ3.countries), ";")})
RETURN BEZ3.countries AS IntermediaryCountries,
BEZ3.name AS Intermediaryname,
BEZ2.countries AS OfficerCountries ,
BEZ2.name AS Officername,
BEZ1.countries as EntityCountries,
BEZ1.name AS Companyname,
BEZ1.address AS CompanyAddress,
SIZE(p.countries) AS NumberofConnections;
Problems with the original:
The CREATE clause was missing a closing } and also a closing ).
The RETURN clause had a dangling AS TOTAL term.
collect (DISTINCT COUNT(p.countries)) was attempting to perform nested aggregation, which is not supported. In any case, even if it had worked, it probably would not have returned what you wanted. I suspect that you actually wanted the size of the p.countries collection, so that is what I used in my query.
I am trying to load large dataset into neo4j-3 and looking for the options. I found one neo4j-import but the problem with that is it is for initial load only. I have to load 2M records around every week.
I tried loading through shell but having some performance issue, I tried following.
1) Creating constraint upfront.
2) Creating Node and relationships in separate query.
3) Heap space 8G
4) dbms.memory.pagecache 4G
Many times the import just hangs and does nothing for hours.
Edit - CSV load being executed:
USING PERIODIC COMMIT 5000
LOAD CSV WITH HEADERS
FROM "file:///my_sds_39_joe.csv"
AS row
OPTIONAL MATCH (per:Person {UID : "Person."+row.player_cardnum})
WHERE per IS NULL
MERGE (p:Person {CardNumber : row.player_cardnum})
ON CREATE SET p.Creation Date = timestamp(), p.Modification Date = timestamp() ;
EDIT
On a second look, seems like you're trying to implement some kind of conditional logic to your insert.
It looks like what you're trying to do is figure out if a :Person exists with a UID (derived from some concatenation with row.player_cardnum), and in the case where that :Person doesn't exist and the match fails, MERGE a :Person with the CardNumber given by row.player_cardnum.
If this is your goal, you're ALMOST there with your query. The problem is with your WHERE clause.
Understand that WHERE clauses are linked with a preceding MATCH, OPTIONAL MATCH, or WITH, and only affects the linked clause.
With that WHERE on that OPTIONAL MATCH, per will always be null, but more importantly, your row will still exist, and the following MERGE will ALWAYS take place for all rows in the CSV. This is probably the source of your slowdown, as it's creating new :Person nodes for all rows.
If you're trying to null out the row completely when the OPTIONAL MATCH hits on an existing :Person (so the MERGE won't happen in that case), you'll need to add a WITH clause, and make sure your WHERE clause is applied to it instead of the OPTIONAL MATCH.
Additionally, make sure that you have either unique constraints or indexes on Person.UID and Person.CardNumber. As for the UID match, I've heard that indexes are not used when there's some kind of string concatenation of the thing you're matching upon, so you may need to assemble it first and pass it in with a WITH.
Your final query would look like this:
USING PERIODIC COMMIT 5000
LOAD CSV WITH HEADERS
FROM "file:///my_sds_39_joe.csv"
AS row
// first build the UID so we can take advantage of the index
WITH row, "Person." + row.player_cardnum AS UID
OPTIONAL MATCH (per:Person {UID : UID})
// the WHERE now applies to the WITH, which will filter out and null out the row when an OPTIONAL MATCH is found
WITH row, per
WHERE per IS NULL
MERGE (p:Person {CardNumber : row.player_cardnum})
ON CREATE SET p.Creation Date = timestamp(), p.Modification Date = timestamp() ;
Assume a Node "Properties". I am using "LOAD CSV with headers..."
Following is the sample file format:
fields
a=100,b=110,c=120,d=500
How do I convert fields column to having a node with a,b,c,d and 100,110,120,500 respectively as the properties of the node "Properties"?
LOAD CSV WITH HEADERS FROM 'file:/sample.tsv' AS row FIELDTERMINATOR '\t'
CREATE (:Properties {props: row.fields})
The above does not create individual properties, but sets a string value to props as "a=100,b=110,c=120,d=500"
Also, different rows could have different set of Key values. That is the key needs to be dynamic. (There are other columns as well, I trimmed it for SO)
fields
a=100,b=110,c=120,d=500
X=300,y=210,Z=420,P=600
...
I am looking for a way to not split this key-value as columns and then load. The reason is they are dynamic - today it is a,b,c,d it may change to aa,bb,cc,dd etc.
I don't want to keep on changing my loader script to recognize new column headers.
Any pointers to solve this? I am using the latest 3.0.1 neo4j version.
First things first: Your file format currently defines a single header/property: fields:
fields
a=100,b=110,c=120,d=500
Since you defined a tab as field terminator, that entire string (a=100,b=110,c=120,d=500) would end up in your node's props property:
To have properties loaded dynamically: First set up proper header:
"a","b","x","y"
1,2,,
,,3,4
Then you can query with something like this:
LOAD CSV WITH HEADERS FROM 'file:///Users/David/overflow.csv' AS row
CREATE (:StackOverflow { a:row.a, b:row.b,x:row.x,y:row.y})
Then when you run something like:
match(so:StackOverflow) return so
You'll get the variable properties you wanted:
I'm trying to create a set of labeled nodes using IMPORT CSV like so:
LOAD CSV WITH HEADERS FROM "file:/D:/OpenData/ProKB/tmp/ErrLink.csv" as line
CREATE (e:ErrLink {kbid:line.Kbid, errnum:line.Errnum })
The CSV file looks like this:
"Kbid:string","Errnum:string"
"S000001080","64"
"S000001096","129"
The problem I'm running into is I'm creating nodes, and they're all property-less. If I get rid of the :string suffixes on the header fields, then the load works.
This is contrary to what Chapter 29.1 of the docs says:
29.1. CSV file header format
The header row of each data source specifies how the fields should be interpreted. The same delimiter is used for the header row as for the rest of the data.
The header contains information for each field, with the format: name:field_type. The name is used as the property key for values, and ignored in other cases. The following field_type settings can be used for both nodes and relationships:
Property value Use one of int, long, float, double, boolean, byte, short, char, string to designate the data type. If no data type is given, this defaults to string. To define an array type, append [] to the type. Array values are by default delimited by a ;, but a different delimiter can be specified.
Is this functionality not working, or is it restricted to just the import tool and not the language?
That section of the documentation is for the Import Tool, which is different than the Cypher language's Load CSV clause.
If you are using the latter, that special header format is not documented, and apparently not supported.