Today in the article, we will see how to perform Neo4J Delete or Reset Databases with examples.

Recently I had a use case where I had to delete existing corrupted data. I wanted to delete the database to allow me to remove outdated or irrelevant data to free up storage space and improve query performance.

However, you may find other use cases like the as below where you want to delete any existing database.

Example Use Cases

• Development and Testing: You might want to delete and recreate your Neo4j database to ensure a clean slate for each iteration. This helps in debugging and verifying that your data import and query processes work correctly.

• Starting Fresh: If you want to start over with a clean slate for a project, and hence you may want to delete the existing database and create a new one with the desired structure and data.

• Migrations and Upgrades: During migrations or database upgrades, you might need to delete the old database and create a new one that is compatible with the latest version of Neo4j.

• Performance Tuning: In some cases, a database may accumulate inefficiencies or performance bottlenecks over time. Deleting and recreating the database can be a way to address these issues and start with an optimized configuration.

Neo4J Delete or Reset All Databases

You may want to delete all databases in Neo4j and start with a clean slate, you can use the following steps:

Step1- Stop Neo4j Server

Before running any delete or cleanup command make sure that the Neo4j server is not running. Please use the below command to stop the neo4j server

neo4j stop

Step2- Remove the entire Graph Databases Directory

You can remove the entire Graph Databases Directory using the below command

Navigate to the Neo4j data directory, which is usually located at $NEO4J_HOME/data/databases/, and delete all the directories and files within the “databases” directory.

rm -rf data/*

OR

rm -rf $NEO4J_HOME/data/*

Note- Please identify the graph directory depending on the OS type ( Mac, Ubuntu, Windows) you are using

Step3 : Start Neo4j

neo4j start

This will remove all existing databases and start with a clean database directory.

Delete all Nodes and Relationships in Neo4j

In Neo4j, if you want to delete specific nodes in a database, you can do so by using a Cypher query to identify and delete those nodes.

Here’s how you can delete selected nodes.

Example 1

MATCH (n)
DETACH DELETE n

The above query could be causing performance issues for a large set of data.

You may use the MATCH clause to execute the query.

Example 2

MATCH (p:Person) 

WHERE p.age < 18 

DETACH DELETE p

Using DETACH DELETE remove all of the nodes and associated relationships.

If you want to delete only the nodes and keep the relationships, you can use the DELETE clause without DETACH. However, this may leave orphaned relationships.

Delete Specific Database in Neo4j

Navigate to the Neo4j data directory, which is usually located at $NEO4J_HOME/data/databases/, and delete the directory corresponding to the database you want to remove.

Example

if you want to delete a database named “testdb” you would delete the directory

 rm -rf $NEO4J_HOME/data/databases/testdb

Using Transaction – To delete All the Nodes and Relationship

BEGIN
MATCH (p:Person)
OPTIONAL MATCH (p)-[rel:RELATIONSHIP_TYPE]-()
DELETE p, rel
COMMIT

Above, please replace the Person with the actual label and “RELATIONSHIP_TYPE” with the type of relationship you want to delete.

Database Transactions are useful for data consistency and preventing issues when dealing with huge database executed with complex operations like node and relationship deletions.

That’s all! Happy coding!

Does this help you fix your issue?

Do you have any better solutions or suggestions? Please sound off your comments below.

Please bookmark this page and share it with your friends. Please Subscribe to the blog to receive notifications on freshly published (2025) best practices and guidelines for software design and development.

The post Neo4J Delete or Reset Databases with examples first appeared on TheCodeBuzz.

Today in this article, we will see how to query the Neo4j Graph – Date Time query with examples.

We will see how to get records based on date/time greater than or less than scenarios.

We will also how to get records between 2 dates range given.

Today in this article, we will cover below aspects,

Getting started

Here below is a sample schema or document we shall use for the date range query,

Neo4j Date Cypher query – Commands with examples

Here we will be using the below query to get the documents between two dates in Neo4j Collection.

Date greater than cypher query

Command

MATCH (n:Node) WHERE n.FieldName > datetime('Date here')
return n

Where

• FieldName – It is a date-time stamp property as expected date format

• Node – the name of the Node.

Date Less than cypher query

Command

MATCH (n:Node) WHERE n.FieldName < datetime('Date here')
return n

Date greater than and less than the query

Command

MATCH (n:Node) WHERE n.FieldName> datetime('date here') AND  n.FieldName< datetime('date here')
return n

Let’s now look few real examples and query execution patterns.

Example – Neo4j Graph – Date Time query – Date Less than

Below is the Neo4j date query for less than dates.

Example

MATCH (n:Person) WHERE n.DateAdded < datetime('2020-06-23')
return n

The above query gives us a total of 264 nodes with relationship details.

Example – Neo4j Date query – greater than dates

Below is the Neo4j query for less than dates.

Query Pattern

MATCH (n:Person) WHERE n.DateAdded > datetime('2020-06-23')
return n

The above query gives us a total of 2 nodes with relationship details.

Neo4j cypher query – Get records between greater than and less than dates

Query Pattern :

MATCH (n:Person) WHERE n.DateAdded > datetime('2009-05-23') AND  n.DateAdded < datetime('2021-06-23')
return n

Example :

The query will identify all the records falling between two specified dates.

References :

• Getting Started with Neo4j GraphDB in C# ASP.NET Core

• Neo4jClient Cypher query in C# ASP.NET Core

Do you have any comments or ideas or any better suggestions to share?

Please sound off your comments below.

Happy Coding !!

Please bookmark this page and share it with your friends. Please Subscribe to the blog to receive notifications on freshly published (2025) best practices and guidelines for software design and development.

The post Neo4j Graph – Date Time query with examples first appeared on TheCodeBuzz.

Today in this article, we will see a sample example to Get Record Count in Neo4j Graph Database.

Today in this article, we will cover below aspects,

Please note that the Neo4j node Database maintains a transactional count store for holding count metadata. Due to some reason when you query the count using aggregation functions like count() , the query returns the result immediately.

Let’s take the example below. I have below 2 nodes with the names Movie and Person.

Get the total count from all Nodes

Lets the total count of records available in all nodes

Query

MATCH (n) RETURN count(n) as count

OR

MATCH () RETURN count(*) as count

Above both queries will return the same result.

Example

Get the total count from specific Nodes

Let’s now get the count of records from a specific node like Movie or Person

Que

Query

MATCH (n:Person)
RETURN count(n) as count

OR

MATCH (:Person)
RETURN count(*) as count

Above both queries will return the same result.

Example

Get the Total Count from specific Nodes using Relationship 

As we discuss above Neo4j node Database maintains a transactional count store for holding count metadata. This also includes counting for relationship patterns.

Query

MATCH ()-[r:ACTED_IN]->(:Movie) RETURN count(r) as count

OR

MATCH (:Person)-[r:ACTED_IN]->() RETURN count(r) as count

Example

Useful References :

• Using Neo4j Database in a C# Console .NET application

• Using Graph Neo4jClient Cypher query in C# ASP.NET Core

Do you have any comments or ideas or any better suggestions to share?

Please sound off your comments below.

Happy Coding !!

Please bookmark this page and share it with your friends. Please Subscribe to the blog to receive notifications on freshly published (2025) best practices and guidelines for software design and development.

The post Get Record Count in Neo4j Graph Node Database first appeared on TheCodeBuzz.

In this article, we shall check how to implement GraphDB – Add Health Check for Neo4j in ASP.NET Core API or MVC applications.

Today in this article, we will cover below aspects,

In our previous Neo4j GraphDB tutorial series, we looked at the basics of GraphDB and also learned how to get started with Graph Cipher query.

• Getting Started with Neo4j -Graph in ASP.NET Core
• Using Neo4jClient Cypher query

In several stages of the application development life cycle, a health check is required.

It allows you to keep real-time track of the health of a variety of resources, databases, and services that your business application relies on.

You can swiftly troubleshoot and resolve technical or environmental concerns as a result of this.

These simple and easy-to-use feature lets you check the status of your resources and dependencies.

GraphDB – Add Health Check for Neo4j

If you already have an API, then please follow below two steps,

Create GraphDB health checks using IHealthCheck interface

Let’s create Create GraphDB health checks using the IHealthCheck interface.

If your API had a dependency on other services or databases then, you can use a similar health check approach or combine them together with different health checks as required.

Step1 – Implement GraphDB IHealthCheck interface

Here please implement the IHealthCheck interface and override the CheckHealthAsync method.

Here we will probe Graph Health check using IGraphClient which is dependency injected in the constructor as below.

GraphHealthCheck check using IHealthCheck where we will implement the interface method as explained below

public class GraphHealthCheck : IHealthCheck
    {
        private readonly IGraphClient _client;
        public GraphHealthCheck(IGraphClient client)
        {
            _client = client;
        }
..
}

Let’s now define the CheckHealthAsync which is the IHealthCheck interface method implemented for Graph connection.

Below is the implementation of the CheckHealthAsync interface method,

public async Task<HealthCheckResult> CheckHealthAsync(HealthCheckContext context, CancellationToken cancellationToken = default)
        {
         
            var healthCheckResultHealthy = await CheckNeo4jGraphConnectionAsync();
            if (healthCheckResultHealthy)
            {
                return HealthCheckResult.Healthy("neo4j graph db health check success");
            }
            return HealthCheckResult.Unhealthy("neo4j graph db health check success"); ;
        }

HealthCheckResult lets you return health as Healthy, Degraded, or Unhealthy statuses.

CheckNeo4jGraphConnectionAsync method is defined as below,

private async Task<bool> CheckNeo4jGraphConnectionAsync()
        {
            try
            {
                await _client.ConnectAsync();
            }
            catch (Exception)
            {
                return false;
            }
            return true;
        }

In the above CheckNeo4jGraphConnectionAsync method, for any connection failure, you shall get an exception that can be used to return the failure status of the method.

Step2 – Register GraphDB health check services

In Startup.ConfigureServices() please add the HealthChecks as below,

Below is a sample Configure method,

 
public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
        {
            if (env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
            }
            app.UseHttpsRedirection();
            app.UseHealthChecks("/healthcheck");
            app.UseRouting();
            app.UseAuthorization();
            app.UseEndpoints(endpoints =>
            {
                endpoints.MapControllers();
            });
        }

Let’s execute the route “/healthcheck” and we shall get the Neo4j Health check success as below,

You shall be able to verify Healthy, Degraded, or Unhealthy status accordingly.

References:

• Getting Started with Neo4j -Graph in ASP.NET Core

• Using Neo4jClient Cypher query

That’s all! Happy coding!

Does this help you fix your issue?

Do you have any better solutions or suggestions? Please sound off your comments below.

Please bookmark this page and share it with your friends. Please Subscribe to the blog to receive notifications on freshly published (2025) best practices and guidelines for software design and development.

The post GraphDB – Add Health Check for Neo4j in ASP.NET Core API first appeared on TheCodeBuzz.