Setup

Verify database is running

This tutorial requires that Aerospike database is running. Before starting the examples below, verify this from a terminal with asinfo (part of the Aerospike Tools package), for example asinfo -v status.

Download and install additional components

Install the Aerospike client for your preferred language in a version with support for expressions.

Java

Add the Aerospike Java client to your project’s Maven pom.xml:

<dependencies>
  <dependency>
    <groupId>com.aerospike</groupId>
    <artifactId>aerospike-client</artifactId>
    <version>10.4</version>
  </dependency>
</dependencies>

Python

Install the Aerospike Python client and its aerospike_helpers package, which provides the expressions used throughout this tutorial.

pip install aerospike

Go

Install the Aerospike Go client, which provides the expression builder functions used throughout this tutorial.

go get github.com/aerospike/aerospike-client-go/v6

C#

Install the Aerospike C# client NuGet package, which provides the expression builder classes used throughout this tutorial.

dotnet add package Aerospike.Client

Node.js

Install the Aerospike Node.js client, which provides the exp module used throughout this tutorial.

npm install aerospike

Rust

Install the Aerospike Rust client, which provides the expression builder functions used throughout this tutorial. The client requires an async runtime; this tutorial uses Tokio.

cargo add tokio --features macros,rt-multi-thread
cargo add aerospike --features rt-tokio

Initialize client

Destructive cleanup

The truncateTestData() helper deletes all records in the tutorial namespace and set. Use a disposable test cluster or confirm the target namespace and set before running it.

Initialize the client. Also, define constants including the namespace test and set expressions and a convenient function truncateTestData.

Java

import com.aerospike.client.AerospikeClient;

AerospikeClient client = new AerospikeClient("localhost", 3000);
System.out.println("Initialized the client and connected to the cluster.");

final String NAMESPACE = "test";
final String SET_NAME = "expressions";

// convenience functions to truncate test data
void truncateTestData() {
    try {
        client.truncate(null, NAMESPACE, SET_NAME, null);
    }
    catch (AerospikeException e) {
        // ignore
    }
}

Output:

Initialized the client and connected to the cluster.

Python

import aerospike

config = {'hosts': [('127.0.0.1', 3000)]}
client = aerospike.client(config).connect()
print("Initialized the client and connected to the cluster.")

NAMESPACE = "test"
SET_NAME = "expressions"

# convenience function to truncate test data
def truncate_test_data():
    try:
        client.truncate(NAMESPACE, SET_NAME, 0)
    except aerospike.exception.AerospikeError:
        pass  # ignore

Output:

Initialized the client and connected to the cluster.

Go

The Go examples in this tutorial build on the following setup, assumed to persist for the rest of this page’s client, NAMESPACE, SET_NAME, and truncateTestData across later code blocks (each block also lists any additional imports it needs).

import (
    "fmt"
    "log"

    as "github.com/aerospike/aerospike-client-go/v6"
)

client, err := as.NewClient("localhost", 3000)
if err != nil {
    log.Fatal(err)
}
fmt.Println("Initialized the client and connected to the cluster.")

const NAMESPACE = "test"
const SET_NAME = "expressions"

// convenience function to truncate test data
func truncateTestData() {
    if err := client.Truncate(nil, NAMESPACE, SET_NAME, nil); err != nil {
        // ignore
    }
}

Output:

Initialized the client and connected to the cluster.

C#

The C# examples in this tutorial build on the following setup, assumed to persist for the rest of this page’s client, NAMESPACE, SET_NAME, and TruncateTestData across later code blocks.

using Aerospike.Client;

Host host = new Host("localhost", 3000);
AerospikeClient client = new AerospikeClient(null, host);
Console.WriteLine("Initialized the client and connected to the cluster.");

const string NAMESPACE = "test";
const string SET_NAME = "expressions";

// convenience function to truncate test data
void TruncateTestData()
{
    client.Truncate(null, NAMESPACE, SET_NAME, null);
}

Output:

Initialized the client and connected to the cluster.

Node.js

The Node.js examples in this tutorial build on the following setup, assumed to persist for the rest of this page’s client, NAMESPACE, SET_NAME, and truncateTestData across later code blocks.

const Aerospike = require('aerospike');
const exp = Aerospike.exp;
const op = Aerospike.operations;

const config = { hosts: '127.0.0.1:3000' };
const client = await Aerospike.connect(config);
console.log('Initialized the client and connected to the cluster.');

const NAMESPACE = 'test';
const SET_NAME = 'expressions';

// convenience function to truncate test data
async function truncateTestData() {
    await client.truncate(NAMESPACE, SET_NAME, 0);
}

Output:

Initialized the client and connected to the cluster.

Rust

The Rust examples in this tutorial build on the following setup, assumed to persist for the rest of this page’s client, NAMESPACE, SET, and truncate_test_data across later code blocks. Each block runs inside an async function, for example #[tokio::main] async fn main() -> aerospike::Result<()> { ... }, so .await and ? are available.

use aerospike::{AdminPolicy, Client, ClientPolicy};

let client = Client::new(&ClientPolicy::default(), &"127.0.0.1:3000".to_string()).await?;
println!("Initialized the client and connected to the cluster.");

const NAMESPACE: &str = "test";
const SET: &str = "expressions";

// convenience function to truncate test data
async fn truncate_test_data(client: &Client) {
    let _ = client.truncate(&AdminPolicy::default(), NAMESPACE, SET, 0).await;
}

Output:

Initialized the client and connected to the cluster.

Access shell commands

You may execute shell commands including Aerospike tools such as aql and asadm from a terminal throughout this tutorial.

Next

Continue to Understanding expressions.