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neo4j | standalone server, or an embeddable component | Graph Database library

 by   neo4j Java Version: 3.3.0-beta01 License: Non-SPDX

 by   neo4j Java Version: 3.3.0-beta01 License: Non-SPDX

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kandi X-RAY | neo4j Summary

neo4j is a Java library typically used in Database, Graph Database, MongoDB, Neo4j applications. neo4j has no bugs, it has no vulnerabilities, it has build file available and it has high support. However neo4j has a Non-SPDX License. You can download it from GitHub, Maven.
Neo4j is available both as a standalone server, or an embeddable component. You can download or try online.
Support
Support
Quality
Quality
Security
Security
License
License
Reuse
Reuse

kandi-support Support

  • neo4j has a highly active ecosystem.
  • It has 9857 star(s) with 2128 fork(s). There are 514 watchers for this library.
  • It had no major release in the last 12 months.
  • There are 247 open issues and 2817 have been closed. On average issues are closed in 30 days. There are 2 open pull requests and 0 closed requests.
  • It has a positive sentiment in the developer community.
  • The latest version of neo4j is 3.3.0-beta01
neo4j Support
Best in #Graph Database
Average in #Graph Database
neo4j Support
Best in #Graph Database
Average in #Graph Database

quality kandi Quality

  • neo4j has 0 bugs and 0 code smells.
neo4j Quality
Best in #Graph Database
Average in #Graph Database
neo4j Quality
Best in #Graph Database
Average in #Graph Database

securitySecurity

  • neo4j has no vulnerabilities reported, and its dependent libraries have no vulnerabilities reported.
  • neo4j code analysis shows 0 unresolved vulnerabilities.
  • There are 0 security hotspots that need review.
neo4j Security
Best in #Graph Database
Average in #Graph Database
neo4j Security
Best in #Graph Database
Average in #Graph Database

license License

  • neo4j has a Non-SPDX License.
  • Non-SPDX licenses can be open source with a non SPDX compliant license, or non open source licenses, and you need to review them closely before use.
neo4j License
Best in #Graph Database
Average in #Graph Database
neo4j License
Best in #Graph Database
Average in #Graph Database

buildReuse

  • neo4j releases are available to install and integrate.
  • Deployable package is available in Maven.
  • Build file is available. You can build the component from source.
  • Installation instructions are not available. Examples and code snippets are available.
  • neo4j saves you 1985042 person hours of effort in developing the same functionality from scratch.
  • It has 819022 lines of code, 67605 functions and 8566 files.
  • It has medium code complexity. Code complexity directly impacts maintainability of the code.
neo4j Reuse
Best in #Graph Database
Average in #Graph Database
neo4j Reuse
Best in #Graph Database
Average in #Graph Database
Top functions reviewed by kandi - BETA

kandi has reviewed neo4j and discovered the below as its top functions. This is intended to give you an instant insight into neo4j implemented functionality, and help decide if they suit your requirements.

  • Checks if two objects are equals .
  • Apply changes to a node .
  • Creates a new instance of AbstractLogger .
  • Writes a schema map value .
  • Attempts to lock the list of nodes that need to be locked .
  • Flush the translation table .
  • Refresh all alive keys in the current node .
  • Converts an expression to an AnyValue .
  • Check the existence of an entity .
  • Reads and validates the next key value batch .

neo4j Key Features

Graphs for Everyone

With brew on macOS

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brew install maven

With apt-get on Ubuntu

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sudo apt install maven openjdk-11-jdk

Running Neo4j

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bin/neo4j start

'Session' object has no attribute 'session'

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databaseSession = databaseConnection.session()
with databaseSession.session() as session:
databaseConnection.session().session()
result = databaseSession.write_transaction(..)
with databaseConnection.session() as session:
     result = session.write_transaction(..)
-----------------------
databaseSession = databaseConnection.session()
with databaseSession.session() as session:
databaseConnection.session().session()
result = databaseSession.write_transaction(..)
with databaseConnection.session() as session:
     result = session.write_transaction(..)
-----------------------
databaseSession = databaseConnection.session()
with databaseSession.session() as session:
databaseConnection.session().session()
result = databaseSession.write_transaction(..)
with databaseConnection.session() as session:
     result = session.write_transaction(..)
-----------------------
databaseSession = databaseConnection.session()
with databaseSession.session() as session:
databaseConnection.session().session()
result = databaseSession.write_transaction(..)
with databaseConnection.session() as session:
     result = session.write_transaction(..)
-----------------------
databaseSession = databaseConnection.session()
with databaseSession.session() as session:
databaseConnection.session().session()
result = databaseSession.write_transaction(..)
with databaseConnection.session() as session:
     result = session.write_transaction(..)

Returning sum of specific node property values Neo4j

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MATCH (n)
RETURN COALESCE(n.alias, n.name) AS name, sum(n.val) AS val
-----------------------
MATCH (n)<-[rel:RELATED_TO]-()
RETURN COALESCE(n.alias, n.name) AS name, count(rel) AS cnt

spring-data-neo4j v6: No converter found capable of converting from type [MyDTO] to type [org.neo4j.driver.Value]

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import mypackage.model.*
import com.fasterxml.jackson.core.type.TypeReference
import com.fasterxml.jackson.module.kotlin.jacksonObjectMapper
import org.neo4j.driver.Value
import org.neo4j.driver.Values
import org.springframework.core.convert.TypeDescriptor
import org.springframework.core.convert.converter.GenericConverter
import org.springframework.core.convert.converter.GenericConverter.ConvertiblePair
import java.util.HashSet

class DtoToNeo4jValueConverter : GenericConverter {
    override fun getConvertibleTypes(): Set<ConvertiblePair>? {
        val convertiblePairs: MutableSet<ConvertiblePair> = HashSet()
        convertiblePairs.add(ConvertiblePair(MyDTO::class.java, Value::class.java))
        return convertiblePairs
    }

    override fun convert(source: Any?, sourceType: TypeDescriptor, targetType: TypeDescriptor?): Any? {
        return if (MyDTO::class.java.isAssignableFrom(sourceType.type)) {
            // generic way of converting an object into a map
            val dataclassAsMap = jacksonObjectMapper().convertValue(source as MyDTO, object :
                    TypeReference<Map<String, Any>>() {})
            Values.value(dataclassAsMap)
        } else null
    }
}
import org.springframework.context.annotation.Bean
import org.springframework.context.annotation.Configuration
import org.springframework.data.neo4j.core.convert.Neo4jConversions
import org.springframework.core.convert.converter.GenericConverter
import java.util.*


@Configuration
class MyNeo4jConfig {
    @Bean
    override fun neo4jConversions(): Neo4jConversions? {
        val additionalConverters: Set<GenericConverter?> = Collections.singleton(DtoToNeo4jValueConverter())
        return Neo4jConversions(additionalConverters)
    }
}
-----------------------
import mypackage.model.*
import com.fasterxml.jackson.core.type.TypeReference
import com.fasterxml.jackson.module.kotlin.jacksonObjectMapper
import org.neo4j.driver.Value
import org.neo4j.driver.Values
import org.springframework.core.convert.TypeDescriptor
import org.springframework.core.convert.converter.GenericConverter
import org.springframework.core.convert.converter.GenericConverter.ConvertiblePair
import java.util.HashSet

class DtoToNeo4jValueConverter : GenericConverter {
    override fun getConvertibleTypes(): Set<ConvertiblePair>? {
        val convertiblePairs: MutableSet<ConvertiblePair> = HashSet()
        convertiblePairs.add(ConvertiblePair(MyDTO::class.java, Value::class.java))
        return convertiblePairs
    }

    override fun convert(source: Any?, sourceType: TypeDescriptor, targetType: TypeDescriptor?): Any? {
        return if (MyDTO::class.java.isAssignableFrom(sourceType.type)) {
            // generic way of converting an object into a map
            val dataclassAsMap = jacksonObjectMapper().convertValue(source as MyDTO, object :
                    TypeReference<Map<String, Any>>() {})
            Values.value(dataclassAsMap)
        } else null
    }
}
import org.springframework.context.annotation.Bean
import org.springframework.context.annotation.Configuration
import org.springframework.data.neo4j.core.convert.Neo4jConversions
import org.springframework.core.convert.converter.GenericConverter
import java.util.*


@Configuration
class MyNeo4jConfig {
    @Bean
    override fun neo4jConversions(): Neo4jConversions? {
        val additionalConverters: Set<GenericConverter?> = Collections.singleton(DtoToNeo4jValueConverter())
        return Neo4jConversions(additionalConverters)
    }
}
-----------------------
@Query("MATCH (u:User) WHERE u.username = :#{#username} SET u.firstName = :#{#up.firstName},u.lastName = :#{#up.firstName},u.intro = :#{#up.intro} RETURN u")
Mono<User> update(@Param("username") String username,@Param("up") UserProfile up);

FIlter the list with a condition in Neo4J

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[x in type WHERE x <> "Thriller" | x]
-----------------------
 RETURN apoc.coll.removeAll(Type, "Thriller") as Type, Name 

Can't load CSV from Drive to Neo4j

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LOAD CSV WITH HEADERS FROM "https://drive.google.com/u/0/uc?id=12DiEwM8XatMZBXA6TdekxWl8qrsgVj3l&export=download" as row
RETURN row LIMIT 5

Is it possible to connect to AuraDB with neomodel?

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from neomodel import config

user = 'neo4j'
psw = 'awesome_password'
uri = 'awesome.databases.neo4j.io'
    
config.DATABASE_URL = 'neo4j+s://{}:{}@{}'.format(user, psw, uri)
print(config.DATABASE_URL)

Result: 

   neo4j+s://neo4j:awesome_password@awesome.databases.neo4j.io

GraphQL Custom directive enforcing value restrictions

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Middleware

import { ValidationError } from "apollo-server-micro";
import { IMiddleware } from "graphql-middleware";
import { Order } from "pages/api/graphql";

export const checkStateMiddleware: IMiddleware = {
  Mutation: {
    updateOrders: async (resolve, parent, args, ctx, info) => {
      const { where, update } = args;

      const [existing] = await Order.find({
        ...where,
      });

      const states = ["UNAPPROVED", "APPROVED", "CANCELLED", "FULLFIELD"];

      const currentState = states.indexOf(existing.state);
      const toBeUpdatedState = states.indexOf(update.state);

      if (toBeUpdatedState < currentState) {
        throw new ValidationError("Can't update value with previous state.");
      }

      return resolve(parent, args);
    },
  },
};
//...
import { applyMiddleware } from "graphql-middleware";
//...
const schemaWithMiddleware = applyMiddleware(schema, checkStateMiddleware);

const apolloServer = new ApolloServer({ schema: schemaWithMiddleware });
//...
-----------------------
Middleware

import { ValidationError } from "apollo-server-micro";
import { IMiddleware } from "graphql-middleware";
import { Order } from "pages/api/graphql";

export const checkStateMiddleware: IMiddleware = {
  Mutation: {
    updateOrders: async (resolve, parent, args, ctx, info) => {
      const { where, update } = args;

      const [existing] = await Order.find({
        ...where,
      });

      const states = ["UNAPPROVED", "APPROVED", "CANCELLED", "FULLFIELD"];

      const currentState = states.indexOf(existing.state);
      const toBeUpdatedState = states.indexOf(update.state);

      if (toBeUpdatedState < currentState) {
        throw new ValidationError("Can't update value with previous state.");
      }

      return resolve(parent, args);
    },
  },
};
//...
import { applyMiddleware } from "graphql-middleware";
//...
const schemaWithMiddleware = applyMiddleware(schema, checkStateMiddleware);

const apolloServer = new ApolloServer({ schema: schemaWithMiddleware });
//...

Neo4j: Get nodes that are at least related with some items of a list

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SELECT recipe_id FROM used_in WHERE ingredient_id = ingedient1
     AND  ingredient_id = ingedient2;
-----------------------
MATCH (i:Ingredient)-[:INGREDIENT_OF]->(r:Recipe)
WITH r, collect(i.name) as recipeIngredients, ['salt', 'pepper'] as    requiredIngredients
WHERE apoc.coll.containsAll(recipeIngredients, requiredIngredients)
RETURN r;

&quot;Connection closed&quot; accessing neo4j in Docker from node.js in Docker on Mac

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services:
  app:
    ...
    deploy:
      resources:
        limits:
          memory: 2g
          cpus: '1.4'
services:
  app:
    networks:
      - backend

networks:
  backend:
    ipam:
      driver: default
      config:
        - subnet: "10.8.0.0/24"
-----------------------
services:
  app:
    ...
    deploy:
      resources:
        limits:
          memory: 2g
          cpus: '1.4'
services:
  app:
    networks:
      - backend

networks:
  backend:
    ipam:
      driver: default
      config:
        - subnet: "10.8.0.0/24"

Parse neo4j JSON response

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const result = {
    "records": [
        {
            "keys": [
                "criteria.name"
            ],
            "length": 1,
            "_fields": [
                "Perspective"
            ],
            "_fieldLookup": {
                "criteria.name": 0
            }
        },
        {
            "keys": [
                "criteria.name"
            ],
            "length": 1,
            "_fields": [
                "3D"
            ],
            "_fieldLookup": {
                "criteria.name": 0
            }
        },
        {
            "keys": [
                "criteria.name"
            ],
            "length": 1,
            "_fields": [
                "2D"
            ],
            "_fieldLookup": {
                "criteria.name": 0
            }
        }
    ],
    "summary": {
        "query": {
            "text": "MATCH (criteria:TEST_01)\nRETURN criteria.name\nLIMIT 3",
            "parameters": {}
        },
        "queryType": "r",
        "counters": {
            "_stats": {
                "nodesCreated": 0,
                "nodesDeleted": 0,
                "relationshipsCreated": 0,
                "relationshipsDeleted": 0,
                "propertiesSet": 0,
                "labelsAdded": 0,
                "labelsRemoved": 0,
                "indexesAdded": 0,
                "indexesRemoved": 0,
                "constraintsAdded": 0,
                "constraintsRemoved": 0
            },
            "_systemUpdates": 0
        },
        "updateStatistics": {
            "_stats": {
                "nodesCreated": 0,
                "nodesDeleted": 0,
                "relationshipsCreated": 0,
                "relationshipsDeleted": 0,
                "propertiesSet": 0,
                "labelsAdded": 0,
                "labelsRemoved": 0,
                "indexesAdded": 0,
                "indexesRemoved": 0,
                "constraintsAdded": 0,
                "constraintsRemoved": 0
            },
            "_systemUpdates": 0
        },
        "plan": false,
        "profile": false,
        "notifications": [],
        "server": {
            "address": "localhost:7687",
            "version": "Neo4j/4.1.0",
            "protocolVersion": 4.1
        },
        "resultConsumedAfter": {
            "low": 2,
            "high": 0
        },
        "resultAvailableAfter": {
            "low": 80,
            "high": 0
        },
        "database": {
            "name": "neo4j"
        }
    }
}

let option1 = [];
let option2 = [];

// For each object in result.records,
for (let val of result.records) {
  // Put everything in val._fields into our result array.
  // ... spreads the array, so all elements are inserted
  // individually in case, in the future,
  // there are multiple items in _fields.
  option1.push(...val._fields);
  
  // For the object you provided, you could just do
  // val._fields[0]. However, option1 is more generalizable
  // in case there's ever more than one thing in _fields.
  option2.push(val._fields[0]);
}

console.log(option1);
console.log(option2);

Community Discussions

Trending Discussions on neo4j
  • 'Session' object has no attribute 'session'
  • Returning sum of specific node property values Neo4j
  • spring-data-neo4j v6: No converter found capable of converting from type [MyDTO] to type [org.neo4j.driver.Value]
  • Gremlin: Return new edges created in a query without saving them (equivalent to APOC vRelationship)
  • FIlter the list with a condition in Neo4J
  • Can't load CSV from Drive to Neo4j
  • Is it possible to connect to AuraDB with neomodel?
  • GraphQL Custom directive enforcing value restrictions
  • Is neo4j 3.5 impacted by CVE-2021-44228?
  • Neo4j: Get nodes that are at least related with some items of a list
Trending Discussions on neo4j

QUESTION

'Session' object has no attribute 'session'

Asked 2022-Apr-05 at 07:20

I am receiving an error

enter image description here

this is my code block (simplified, but still demonstrates error)

import neo4j
import sys
import uuid

from neo4j import GraphDatabase


def create_population_point(tx, _point, _uuid, _tl, _tr, _ll, _lr, _band):
    print("Add a record block  A")
    tx.run("CREATE (n:Population_Point 
    {point:$point,uuid:$uuid,TL:$tl,TR:$tr,BL:$bl,BR:$br,Band_1:$band}),"
          "point=_point,uuid=_uuid,tl=_tl,tr=_tr,ll=_ll,lr=_lr,band=_band")


def main():
uri = "neo4j://localhost:7687"
username = "neo4j"
password = "P@ssword2"

databaseConnection = GraphDatabase.driver(uri, auth=(username, password))
databaseSession = databaseConnection.session()
print("Connection established")
print("Variables assigned values")
_point = "D007_S001_T001"
_uuid = uuid.uuid4()
_tl = "28.27291"
_tr = "-81.65765"
_ll = "28.27291"
_lr = "-81.65765"
_band = "455"
print("Ready to execute")
with databaseSession.session() as session:
    result = session.write_transaction(create_population_point, _point, _uuid, _tl, _tr, _ll, 
   _lr, _band)
databaseConnection.close()
print("Connection closed")


if __name__ == "__main__":
    main()

This is the line that is throwing the error

with databaseSession.session() as session:

running python 3.10.4

ANSWER

Answered 2022-Apr-05 at 07:20

First you create

databaseSession = databaseConnection.session()

next you use

with databaseSession.session() as session:

so finally you try to use

databaseConnection.session().session()

and this is wrong.

You could use directly

result = databaseSession.write_transaction(..)

or use databaseConnection instead of databaseSession in

with databaseConnection.session() as session:
     result = session.write_transaction(..)

(and remove databaseSession = databaseConnection.session() because you don't use it)

Source https://stackoverflow.com/questions/71745651

Community Discussions, Code Snippets contain sources that include Stack Exchange Network

Vulnerabilities

No vulnerabilities reported

Install neo4j

You can download it from GitHub, Maven.
You can use neo4j like any standard Java library. Please include the the jar files in your classpath. You can also use any IDE and you can run and debug the neo4j component as you would do with any other Java program. Best practice is to use a build tool that supports dependency management such as Maven or Gradle. For Maven installation, please refer maven.apache.org. For Gradle installation, please refer gradle.org .

Support

For any new features, suggestions and bugs create an issue on GitHub. If you have any questions check and ask questions on community page Stack Overflow .

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