Khóa học miễn phí Neo4j – Count Function nhận dự án làm có lương

Neo4j – Count Function

Assume we have created a graph in the database with the following details.

Count

The count() function is used to count the number of rows.

Syntax

Following is the syntax of the count function.

MATCH (n { name: ''A'' })-->(x)
RETURN n, count(&ast;)

Example

Following is a sample Cypher Query which demonstrates the usage of the count() function.

Match(n{name: "India", result: "Winners"})--(x)
RETURN n, count(*)

To execute the above query, carry out the following steps −

Step 1 − Open the Neo4j desktop App and start the Neo4j Server. Open the built-in browser app of Neo4j using the URL http://localhost:7474/ as shown in the following screenshot.

Step 2 − Copy and paste the desired query in the dollar prompt and press the play button (to execute the query) highlighted in the following screenshot.

Result

On executing, you will get the following result.

Group Count

The COUNT clause is also used to count the groups of relationship types.

Example

Following is a sample Cypher Query which counts and returns the number of nodes participating in each relation.

Match(n{name: "India", result: "Winners"})-[r]-(x)
RETURN type (r), count(*)

To execute the above query, carry out the following steps −

Step 1 − Open the Neo4j desktop App and start the Neo4j Server. Open the built-in browser app of Neo4j using the URL http://localhost:7474/ as shown in the following screenshot.

Step 2 − Copy and paste the desired query in the dollar prompt and press the play button (to execute the query) highlighted in the following screenshot.

Result

On executing, you will get the following result.

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August 17, 2024

Khóa học miễn phí Neo4j – Limit Clause nhận dự án làm có lương

Neo4j – Limit Clause

The limit clause is used to limit the number of rows in the output.

Syntax

Following is the syntax of the LIMIT clause.

MATCH (n)
RETURN n
ORDER BY n.name
LIMIT 3

Example

Before proceeding with the example, create 5 nodes in the Neo4j database as shown below.

CREATE(Dhawan:player{name:"shikar Dhawan", YOB: 1985, runs:363, country: "India"})
CREATE(Jonathan:player{name:"Jonathan Trott", YOB:1981, runs:229, country:"South Africa"})
CREATE(Sangakkara:player{name:"Kumar Sangakkara", YOB:1977, runs:222, country:"Srilanka"})
CREATE(Rohit:player{name:"Rohit Sharma", YOB: 1987, runs:177, country:"India"})
CREATE(Virat:player{name:"Virat Kohli", YOB: 1988, runs:176, country:"India"})

Following is a sample Cypher Query which returns the nodes created above in a descending order and limits the records in the result to 3.

MATCH (n)
RETURN n.name, n.runs
ORDER BY n.runs DESC
LIMIT 3

To execute the above query, carry out the following steps −

Step 1 − Open the Neo4j desktop App and start the Neo4j Server. Open the built-in browser app of Neo4j using the URL http://localhost:7474/ as shown in the following screenshot.

Step 2 − Copy and paste the desired query in the dollar prompt and press the play button (to execute the query) highlighted in the following screenshot.

Result

On executing, you will get the following result.

Limit with expression

You can also use the LIMIT clause with expression.

Example

Following is a sample Cypher Query which limits the records using an expression.

MATCH (n)
RETURN n.name, n.runs
ORDER BY n.runs DESC
LIMIT toInt(3 * rand())+ 1

To execute the above query, carry out the following steps −

Step 1 − Open the Neo4j desktop App and start the Neo4j Server. Open the built-in browser app of Neo4j using the URL http://localhost:7474/ as shown in the following screenshot.

Step 2 − Copy and paste the desired query in the dollar prompt and press the play button (to execute the query) highlighted in the following screenshot.

Result

On executing, you will get the following result.

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August 17, 2024

Khóa học miễn phí Neo4j CQL – Creating a Relationship nhận dự án làm có lương

Neo4j CQL – Creating a Relationship

In Noe4j, a relationship is an element using which we connect two nodes of a graph. These relationships have direction, type, and the form patterns of data. This chapter teaches you how to −

Create relationships
Create a relationship between the existing nodes
Create a relationship with label and properties

Creating Relationships

We can create a relationship using the CREATE clause. We will specify relationship within the square braces “[ ]” depending on the direction of the relationship it is placed between hyphen “ – ” and arrow “ → ” as shown in the following syntax.

Syntax

Following is the syntax to create a relationship using the CREATE clause.

CREATE (node1)-[:RelationshipType]->(node2)

Example

First of all, create two nodes Ind and Dhawan in the database, as shown below.

CREATE (Dhawan:player{name: "Shikar Dhawan", YOB: 1985, POB: "Delhi"})
CREATE (Ind:Country {name: "India"})

Now, create a relationship named BATSMAN_OF between these two nodes as −

CREATE (Dhawan)-[r:BATSMAN_OF]->(Ind)

Finally, return both the nodes to see the created relationship.

RETURN Dhawan, Ind

Copy and paste the desired query in the dollar prompt and press the play button (to execute the query) highlighted in the following screenshot.

Result

On executing, you will get the following result.

Creating a Relationship Between the Existing Nodes

You can also create a relationship between the existing nodes using the MATCH clause.

Syntax

Following is the syntax to create a relationship using the MATCH clause.

MATCH (a:LabeofNode1), (b:LabeofNode2)
   WHERE a.name = "nameofnode1" AND b.name = " nameofnode2"
CREATE (a)-[: Relation]->(b)
RETURN a,b

Example

Following is a sample Cypher Query which creates a relationship using the match clause.

MATCH (a:player), (b:Country) WHERE a.name = "Shikar Dhawan" AND b.name = "India"
CREATE (a)-[r: BATSMAN_OF]->(b)
RETURN a,b

To execute the above query, carry out the following steps.

Step 1 − Open the Neo4j desktop App and start the Neo4j Server. Open the built-in browser app of Neo4j using the URL http://localhost:7474/ as shown in the following screenshot.

Step 2 − Copy and paste the desired query in the dollar prompt and press the play button (to execute the query) highlighted in the following screenshot.

Result

On executing, you will get the following result.

Creating a Relationship with Label and Properties

You can create a relationship with label and properties using the CREATE clause.

Syntax

Following is the syntax to create a relationship with label and properties using the CREATE clause.

CREATE (node1)-[label:Rel_Type {key1:value1, key2:value2, . . . n}]-> (node2)

Example

Following is a sample Cypher Query which creates a relationship with label and properties.

MATCH (a:player), (b:Country) WHERE a.name = "Shikar Dhawan" AND b.name = "India"
CREATE (a)-[r:BATSMAN_OF {Matches:5, Avg:90.75}]->(b)
RETURN a,b

To execute the above query, carry out the following steps −

Step 1 − Open the Neo4j desktop App and start the Neo4j Server. Open the built-in browser app of Neo4j using the URL http://localhost:7474/ as shown in the following screenshot.

Step 2 − Copy and paste the desired query in the dollar prompt and press the play button (to execute the query) highlighted in the following screenshot.

Result

On executing, you will get the following result.

Creating a Complete Path

In Neo4j, a path is formed using continuous relationships. A path can be created using the create clause.

Syntax

Following is the syntax to create a path in Neo4j using the CREATE clause.

CREATE p = (Node1 {properties})-[:Relationship_Type]->
   (Node2 {properties})[:Relationship_Type]->(Node3 {properties})
RETURN p

Example

To execute the above query, carry out the following steps −

Step 1 − Open the Neo4j desktop App and start the Neo4j Server. Open the built-in browser app of Neo4j using the URL http://localhost:7474/ as shown in the following screenshot.

Step 2 − Copy and paste the desired query in the dollar prompt and press the play button (to execute the query) highlighted in the following screenshot.

Result

On executing, you will get the following result.

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August 17, 2024

Khóa học miễn phí Neo4j – Set Clause nhận dự án làm có lương

Neo4j – Set Clause

Using Set clause, you can add new properties to an existing Node or Relationship, and also add or update existing Properties values.

In this chapter, we are going to discuss how to −

Set a property
Remove a property
Set multiple properties
Set a label on a node
Set multiple labels on a node

Setting a Property

Using the SET clause, you can create a new property in a node.

Syntax

Following is the syntax for setting a property.

MATCH (node:label{properties . . . . . . . . . . . . . . })
SET node.property = value
RETURN node

Example

Before proceeding with the example, first create a node named Dhawan as shown below.

CREATE (Dhawan:player{name: "shikar Dhawan", YOB: 1985, POB: "Delhi"})

Following is a sample Cypher Query to create a property named “highestscore” with value “187”.

MATCH (Dhawan:player{name: "shikar Dhawan", YOB: 1985, POB: "Delhi"})
SET Dhawan.highestscore = 187
RETURN Dhawan

To execute the above query, carry out the following steps −

Step 1 − Open the Neo4j desktop App and start the Neo4j Server. Open the built-in browser app of Neo4j using the URL http://localhost:7474/ as shown in the following screnshot.

Step 2 − Copy and paste the desired query in the dollar prompt and press the play button (to execute the query) highlighted in the following screenshot.

Result

On executing, you will get the following result. Here you can observe that a property with a key-value pair highestscore/187 is created in the node named “Dhawan”.

Removing a Property

You can remove an existing property by passing NULL as value to it.

Syntax

Following is the syntax of removing a property from a node using the SET clause.

MATCH (node:label {properties})
SET node.property = NULL
RETURN node

Example

Before proceeding with the example, first create a node “jadeja” as shown below.

Create (Jadeja:player {name: "Ravindra Jadeja", YOB: 1988, POB: "NavagamGhed"})

Following is a sample Cypher Query which removes the property named POB from this node using the SET clause as shown below.

MATCH (Jadeja:player {name: "Ravindra Jadeja", YOB: 1988, POB: "NavagamGhed"})
SET Jadeja.POB = NULL
RETURN Jadeja

To execute the above query, carry out the following steps −

Step 1 − Open the Neo4j desktop App and start the Neo4j Server. Open the built-in browser app of Neo4j using the URL http://localhost:7474/ as shown in the following screenshot.

Step 2 − Copy and paste the desired query in the dollar prompt and press the play button (to execute the query) highlighted in the following screenshot.

Result

On executing, you will get the following result. Here you can observe that the variable named POB was deleted.

Setting Multiple Properties

In the same way, you can create multiple properties in a node using the Set clause. To do so, you need to specify these key value pairs with commas.

Syntax

Following is the syntax to create multiple properties in a node using the SET clause.

MATCH (node:label {properties})
SET node.property1 = value, node.property2 = value
RETURN node

Example

Following is a sample Cypher Query which creates multiple properties in a node using the SET clause in Neo4j.

MATCH (Jadeja:player {name: "Ravindra Jadeja", YOB: 1988})
SET Jadeja.POB: "NavagamGhed", Jadeja.HS = "90"
RETURN Jadeja

To execute the above query, carry out the following steps −

Step 1 − Open the Neo4j desktop App and start the Neo4j Server. Open the built-in browser app of Neo4j using the URL http://localhost:7474/ as shown in the following screenshot.

Step 2 − Copy and paste the desired query in the dollar prompt and press the play button (to execute the query) highlighted in the following screenshot.

Result

On executing, you will get the following result. Here you can observe that properties named POB and HS were created.

Setting a Label on a Node

You can set a label to an existing node using the SET clause.

Syntax

Following is the syntax to set a label to an existing node.

MATCH (n {properties . . . . . . . })
SET n :label
RETURN n

Example

Before proceeding with the example, first create a node “Anderson” as shown below.

CREATE (Anderson {name: "James Anderson", YOB: 1982, POB: "Burnely"})

Following is a sample Cypher Query to set a label on a node using the SET clause. This query adds the label “player” to the node Anderson and returns it.

MATCH (Anderson {name: "James Anderson", YOB: 1982, POB: "Burnely"})
SET Anderson: player
RETURN Anderson

To execute the above query, carry out the following steps −

Step 1 − Open the Neo4j desktop App and start the Neo4j Server. Open the built-in browser app of Neo4j using the URL http://localhost:7474/ as shown in the following screenshot.

Step 2 − Copy and paste the desired query in the dollar prompt and press the play button (to execute the query) highlighted in the following screenshot.

Result

On executing, you will get the following result. Here you can observe that the label named “player” is added to the node.

Setting Multiple Labels on a Node

You can set multiple labels to an existing node using the SET clause. Here you need to specify the labels by separating them with colons “:”.

Syntax

Following is the syntax to set multiple labels to an existing node using the SET clause.

MATCH (n {properties . . . . . . . })
SET n :label1:label2
RETURN n

Example

Before proceeding with the example, first create a node named “Ishant” as shown below.

CREATE (Ishant {name: "Ishant Sharma", YOB: 1988, POB: "Delhi"})

Following is a sample Cypher Query used to create multiple labels on a node using the SET clause.

MATCH (Ishant {name: "Ishant Sharma", YOB: 1988, POB: "Delhi"})
SET Ishant: player:person
RETURN Ishant

To execute the above query, carry out the following steps −

Step 1 − Open the Neo4j desktop App and start the Neo4j Server. Open the built-in browser app of Neo4j using the URL http://localhost:7474/ as shown in the following screenshot.

Step 2 − Copy and paste the desired query in the dollar prompt and press the play button (to execute the query) highlighted in the following screenshot.

Result

On executing, you will get the following result. Here you can observe that two labels – person and player – are added to the node named Ishant.

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August 17, 2024

Khóa học miễn phí Neo4j CQL – Introduction nhận dự án làm có lương

Neo4j CQL – Introduction

CQL stands for Cypher Query Language. Like Oracle Database has query language SQL, Neo4j has CQL as query language.

Neo4j CQL

Is a query language for Neo4j Graph Database.
Is a declarative pattern-matching language.
Follows SQL like syntax.
Syntax is very simple and in human readable format.

Like Oracle SQL

Neo4j CQL has commands to perform Database operations.
Neo4j CQL supports many clauses such as WHERE, ORDER BY, etc., to write very complex queries in an easy manner.
Neo4j CQL supports some functions such as String, Aggregation. In addition to them, it also supports some Relationship Functions.

Neo4j CQL Clauses

Following are the read clauses of Neo4j Cypher Query Language −

Sr.No	Read Clauses	Usage
1	MATCH	This clause is used to search the data with a specified pattern.
2	OPTIONAL MATCH	This is the same as match, the only difference being it can use nulls in case of missing parts of the pattern.
3	WHERE	This clause id is used to add contents to the CQL queries.
4	START	This clause is used to find the starting points through the legacy indexes.
5	LOAD CSV	This clause is used to import data from CSV files.

Following are the write clauses of Neo4j Cypher Query Language −

Sr.No	Write Clause	Usage
1	CREATE	This clause is used to create nodes, relationships, and properties.
2	MERGE	This clause verifies whether the specified pattern exists in the graph. If not, it creates the pattern.
3	SET	This clause is used to update labels on nodes, properties on nodes and relationships.
4	DELETE	This clause is used to delete nodes and relationships or paths etc. from the graph.
5	REMOVE	This clause is used to remove properties and elements from nodes and relationships.
6	FOREACH	This class is used to update the data within a list.
7	CREATE UNIQUE	Using the clauses CREATE and MATCH, you can get a unique pattern by matching the existing pattern and creating the missing one.
8	Importing CSV files with Cypher	Using Load CSV you can import data from .csv files.

Following are the general clauses of Neo4j Cypher Query Language −

Sr.No	General Clauses	Usage
1	RETURN	This clause is used to define what to include in the query result set.
2	ORDER BY	This clause is used to arrange the output of a query in order. It is used along with the clauses RETURN or WITH.
3	LIMIT	This clause is used to limit the rows in the result to a specific value.
4	SKIP	This clause is used to define from which row to start including the rows in the output.
5	WITH	This clause is used to chain the query parts together.
6	UNWIND	This clause is used to expand a list into a sequence of rows.
7	UNION	This clause is used to combine the result of multiple queries.
8	CALL	This clause is used to invoke a procedure deployed in the database.

Neo4j CQL Functions

Following are the frequently used Neo4j CQL Functions −

Sr.No	CQL Functions	Usage
1	String	They are used to work with String literals.
2	Aggregation	They are used to perform some aggregation operations on CQL Query results.
3	Relationship	They are used to get details of relationships such as startnode, endnode, etc.

We will discuss all Neo4j CQL commands, clauses and functions syntax, usage and examples in-detail in the subsequent chapters.

Neo4j CQL Data Types

These data types are similar to Java language. They are used to define properties of a node or a relationship.

Neo4j CQL supports the following data types −

Sr.No	CQL Data Type	Usage
1	Boolean	It is used to represent Boolean literals: true, false.
2	byte	It is used to represent 8-bit integers.
3	short	It is used to represent 16-bit integers.
4	int	It is used to represent 32-bit integers.
5	long	It is used to represent 64-bit integers.
6	float	It is used to represent 32-bit floating-point numbers.
7	double	It is used to represent 64-bit floating-point numbers.
8	char	It is used to represent 16-bit characters.
9	String	It is used to represent Strings.

CQL Operators

Following are the list of operators supported by Neo4j Cypher Query language.

Sr.No	Type	Operators
1	Mathematical	+, -, *, /, %, ^
2	Comparison	+, <>, <, >, <=, >=
3	Boolean	AND, OR, XOR, NOT
4	String	+
5	List	+, IN, [X], [X…..Y]
6	Regular Expression	=-
7	String matching	STARTS WITH, ENDS WITH, CONSTRAINTS

Boolean Operators in Neo4j CQL

Neo4j supports the following Boolean operators to use in Neo4j CQL WHERE clause to support multiple conditions.

Sr.No	Boolean Operators	Description
1	AND	It is a Neo4j CQL keyword to support AND operation. It is like SQL AND operator.
2	OR	It is a Neo4j CQL keyword to support OR operation. It is like SQL AND operator.
3	NOT	It is a Neo4j CQL keyword to support NOT operation. It is like SQL AND operator.
4	XOR	It is a Neo4j CQL keyword to support XOR operation. It is like SQL AND operator.

Comparison Operators in Neo4j CQL

Neo4j supports the following Comparison operators to use in Neo4j CQL WHERE clause to support conditions.

Sr.No	Boolean Operators	Description
1	=	It is a Neo4j CQL “Equal To” operator.
2	< >	It is a Neo4j CQL “Not Equal To” operator.
3	<	It is a Neo4j CQL “Less Than” operator.
4	>	It is a Neo4j CQL “Greater Than” operator.
5	<=	It is a Neo4j CQL “Less Than Or Equal To” operator.
6	> =	It is a Neo4j CQL “Greater Than Or Equal To” operator.

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August 17, 2024

Khóa học miễn phí Neo4j – Overview nhận dự án làm có lương

Neo4j – Overview

Neo4j is the world”s leading open source Graph Database which is developed using Java technology. It is highly scalable and schema free (NoSQL).

What is a Graph Database?

A graph is a pictorial representation of a set of objects where some pairs of objects are connected by links. It is composed of two elements – nodes (vertices) and relationships (edges).

Graph database is a database used to model the data in the form of graph. In here, the nodes of a graph depict the entities while the relationships depict the association of these nodes.

Popular Graph Databases

Neo4j is a popular Graph Database. Other Graph Databases are Oracle NoSQL Database, OrientDB, HypherGraphDB, GraphBase, InfiniteGraph, and AllegroGraph.

Why Graph Databases?

Nowadays, most of the data exists in the form of the relationship between different objects and more often, the relationship between the data is more valuable than the data itself.

Relational databases store highly structured data which have several records storing the same type of data so they can be used to store structured data and, they do not store the relationships between the data.

Unlike other databases, graph databases store relationships and connections as first-class entities.

The data model for graph databases is simpler compared to other databases and, they can be used with OLTP systems. They provide features like transactional integrity and operational availability.

RDBMS Vs Graph Database

Following is the table which compares Relational databases and Graph databases.

Sr.No	RDBMS	Graph Database
1	Tables	Graphs
2	Rows	Nodes
3	Columns and Data	Properties and its values
4	Constraints	Relationships
5	Joins	Traversal

Advantages of Neo4j

Following are the advantages of Neo4j.

Flexible data model − Neo4j provides a flexible simple and yet powerful data model, which can be easily changed according to the applications and industries.
Real-time insights − Neo4j provides results based on real-time data.
High availability − Neo4j is highly available for large enterprise real-time applications with transactional guarantees.
Connected and semi structures data − Using Neo4j, you can easily represent connected and semi-structured data.
Easy retrieval − Using Neo4j, you can not only represent but also easily retrieve (traverse/navigate) connected data faster when compared to other databases.
Cypher query language − Neo4j provides a declarative query language to represent the graph visually, using an ascii-art syntax. The commands of this language are in human readable format and very easy to learn.
No joins − Using Neo4j, it does NOT require complex joins to retrieve connected/related data as it is very easy to retrieve its adjacent node or relationship details without joins or indexes.

Features of Neo4j

Following are the notable features of Neo4j −

Data model (flexible schema) − Neo4j follows a data model named native property graph model. Here, the graph contains nodes (entities) and these nodes are connected with each other (depicted by relationships). Nodes and relationships store data in key-value pairs known as properties.

In Neo4j, there is no need to follow a fixed schema. You can add or remove properties as per requirement. It also provides schema constraints.
ACID properties − Neo4j supports full ACID (Atomicity, Consistency, Isolation, and Durability) rules.
Scalability and reliability − You can scale the database by increasing the number of reads/writes, and the volume without effecting the query processing speed and data integrity. Neo4j also provides support for replication for data safety and reliability.
Cypher Query Language − Neo4j provides a powerful declarative query language known as Cypher. It uses ASCII-art for depicting graphs. Cypher is easy to learn and can be used to create and retrieve relations between data without using the complex queries like Joins.
Built-in web application − Neo4j provides a built-in Neo4j Browser web application. Using this, you can create and query your graph data.
Drivers − Neo4j can work with −
- REST API to work with programming languages such as Java, Spring, Scala etc.
- Java Script to work with UI MVC frameworks such as Node JS.
- It supports two kinds of Java API: Cypher API and Native Java API to develop Java applications. In addition to these, you can also work with other databases such as MongoDB, Cassandra, etc.
Indexing − Neo4j supports Indexes by using Apache Lucence.

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August 17, 2024

Khóa học miễn phí Neo4j CQL – Creating Nodes nhận dự án làm có lương

Neo4j CQL – Creating Nodes

As discussed, a node is a data/record in a graph database. You can create a node in Neo4j using the CREATE clause. This chapter teaches you how to −

Creating a Single node

You can create a node in Neo4j by simply specifying the name of the node that is to be created along with the CREATE clause.

Syntax

Following is the syntax for creating a node using Cypher Query Language.

CREATE (node_name);

Note − Semicolon (;) is optional.

Example

Following is a sample Cypher Query which creates a node in Neo4j.

CREATE (sample)

To execute the above query, carry out the following steps −

Step 1 − Open the Neo4j desktop App and start the Neo4j Server as shown in the following screenshot.

Step 2 − Open your browser, copy paste the following URL in your address bar http://localhost:7474/. This will give you the built-in browser app of Neo4j with a dollar prompt as shown in the following screenshot.

Step 3 − Copy and paste the desired query in the dollar prompt and press the play button (to execute the query) highlighted in the following screenshot.

Result

On executing, you will get the following result.

Verification

To verify the creation of the node type, execute the following query in the dollar prompt.

MATCH (n) RETURN n

This query returns all the nodes in the database (we will discuss this query in detail in the coming chapters).

On executing, this query shows the created node as shown in the following screenshot.

Creating Multiple Nodes

The create clause of Neo4j CQL is also used to create multiple nodes at the same time. To do so, you need to pass the names of the nodes to be created, separated by a comma.

Syntax

Following is the syntax to create multiple nodes using the CREATE clause.

CREATE (node1),(node2)

Example

Following is a sample Cypher Query which creates multiple nodes in Neo4j.

CREATE (sample1),(sample2)

To execute the above query, carry out the following steps −

Step 1 − Open the Neo4j desktop App and start the Neo4j Server. Open the built-in browser app of Neo4j using the URL http://localhost:7474/ as shown in the following screenshot.

Step 2 − Copy and paste the desired query in the dollar prompt and press the play button (to execute the query) highlighted in the following screenshot.

Result

On executing, you will get the following result.

Verification

To verify the creation of the node, type and execute the following query in the dollar prompt.

MATCH (n) RETURN n

This query returns all the nodes in the database (we will discuss this query in detail in the coming chapters).

On executing, this query shows the created node as shown in the following screenshot.

Creating a Node with a Label

A label in Neo4j is used to group (classify) the nodes using labels. You can create a label for a node in Neo4j using the CREATE clause.

Syntax

Following is the syntax for creating a node with a label using Cypher Query Language.

CREATE (node:label)

Example

Following is a sample Cypher Query which creates a node with a label.

CREATE (Dhawan:player)

To execute the above query, carry out the following steps −

Step 1 − Open the Neo4j desktop App and start the Neo4j Server. Open the built-in browser app of Neo4j using the URL http://localhost:7474/ as shown in the following screenshot.

Step 2 − Copy and paste the desired query in the dollar prompt and press the play button (to execute the query) highlighted in the following screenshot.

Result

On executing, you will get the following result.

Verification

To verify the creation of the node, type and execute the following query in the dollar prompt.

MATCH (n) RETURN n

This query returns all the nodes in the database (we will discuss this query in detail in the coming chapters).

On executing, this query shows the created node as shown in the following screenshot.

Creating a Node with Multiple Labels

You can also create multiple labels for a single node. You need to specify the labels for the node by separating them with a colon “ : ”.

Syntax

Following is the syntax to create a node with multiple labels.

CREATE (node:label1:label2:. . . . labeln)

Example

Following is a sample Cypher Query which creates a node with multiple labels in Neo4j.

CREATE (Dhawan:person:player)

To execute the above query, carry out the following steps −

Step 1 − Open the Neo4j desktop App and start the Neo4j Server. Open the built-in browser app of Neo4j using the URL http://localhost:7474/ as shown in the following screenshot.

Step 2 − Copy and paste the desired query in the dollar prompt and press the play button (to execute the query) highlighted in the following screenshot.

Result

On executing, you will get the following result.

Verification

To verify the creation of the node, type and execute the following query in the dollar prompt.

MATCH (n) RETURN n

This query returns all the nodes in the database (we will discuss this query in detail in the coming chapters).

On executing, this query shows the created node as shown in the following screenshot.

Create Node with Properties

Properties are the key-value pairs using which a node stores data. You can create a node with properties using the CREATE clause. You need to specify these properties separated by commas within the flower braces “{ }”.

Syntax

Following is the syntax to create a node with properties.

CREATE (node:label { key1: value, key2: value, . . . . . . . . .  })

Example

Following is a sample Cypher Query which creates a node with properties.

CREATE (Dhawan:player{name: "Shikar Dhawan", YOB: 1985, POB: "Delhi"})

To execute the above query, carry out the following steps −

Step 1 − Open the Neo4j desktop App and start the Neo4j Server. Open the built-in browser app of Neo4j using the URL http://localhost:7474/ as shown in the following screenshot.

Step 2 − Copy and paste the desired query in the dollar prompt and press the play button (to execute the query) highlighted in the following screenshot.

Result

On executing, you will get the following result.

Verification

To verify the creation of the node, type and execute the following query in the dollar prompt.

MATCH (n) RETURN n

This query returns all the nodes in the database (we will discuss this query in detail in the coming chapters).

On executing, this query shows the created node as shown in the following screenshot.

Returning the Created Node

Throughout the chapter, we used the MATCH (n) RETURN n query to view the created nodes. This query returns all the existing nodes in the database.

Instead of this, we can use the RETURN clause with CREATE to view the newly created node.

Syntax

Following is the syntax to return a node in Neo4j.

CREATE (Node:Label{properties. . . . }) RETURN Node

Example

Following is a sample Cypher Query which creates a node with properties and returns it.

CREATE (Dhawan:player{name: "Shikar Dhawan", YOB: 1985, POB: "Delhi"}) RETURN Dhawan

To execute the above query, carry out the following steps −

Step 1 − Open the Neo4j desktop App and start the Neo4j Server. Open the built-in browser app of Neo4j using the URL http://localhost:7474/ as shown in the following screenshot.

Step 2 − Copy and paste the desired query in the dollar prompt and press the play button (to execute the query) highlighted in the following screenshot.

Result

On executing, you will get the following result.

Khóa học lập trình tại Toidayhoc vừa học vừa làm dự án vừa nhận lương: Khóa học lập trình nhận lương tại trung tâm Toidayhoc

August 17, 2024

Category: neo4j

Neo4j – Count Function

Count

Syntax

Example

Result

Group Count

Example

Result

Neo4j – Limit Clause

Syntax

Example

Result

Limit with expression

Example

Result

Neo4j CQL – Creating a Relationship

Creating Relationships

Syntax

Example

Result

Creating a Relationship Between the Existing Nodes

Syntax

Example

Result

Creating a Relationship with Label and Properties

Syntax

Example

Result

Creating a Complete Path

Syntax

Example

Result

Neo4j – Set Clause

Setting a Property

Syntax

Example

Result

Removing a Property

Syntax

Example

Result

Setting Multiple Properties

Syntax

Example

Result

Setting a Label on a Node

Syntax

Example

Result

Setting Multiple Labels on a Node

Syntax

Example

Result

Neo4j CQL – Introduction

Neo4j CQL

Like Oracle SQL

Neo4j CQL Clauses

Neo4j CQL Functions

Neo4j CQL Data Types

CQL Operators

Boolean Operators in Neo4j CQL

Comparison Operators in Neo4j CQL

Neo4j – Overview

What is a Graph Database?

Popular Graph Databases

Why Graph Databases?

RDBMS Vs Graph Database

Advantages of Neo4j

Features of Neo4j

Neo4j CQL – Creating Nodes

Creating a Single node

Syntax

Example

Result

Verification

Creating Multiple Nodes

Syntax

Example

Result