PHP guide

Connect your PHP application to a Redis database

Predis is the recommended PHP client for Redis. The sections below explain how to install Predis and connect your application to a Redis database.

Note:
Although we provide basic documentation for Predis, it is a third-party client library and is not developed or supported directly by Redis.

Predis requires a running Redis or Redis Stack server. See Getting started for Redis installation instructions.

Install

Use Composer to install the Predis library with the following command line:

composer require predis/predis

Connect

Connect to a locally-running server on the standard port (6379) with the following code:

<?php

require 'vendor/autoload.php';

use Predis\Client as PredisClient;

$r = new PredisClient();

Store and retrieve a simple string to test the connection:

echo $r->set('foo', 'bar'), PHP_EOL;
// >>> OK

echo $r->get('foo'), PHP_EOL;
// >>> bar

Store and retrieve a hash object:

$r->hset('user-session:123', 'name', 'John');
$r->hset('user-session:123', 'surname', 'Smith');
$r->hset('user-session:123', 'company', 'Redis');
$r->hset('user-session:123', 'age', 29);

echo var_export($r->hgetall('user-session:123')), PHP_EOL;
/* >>>
array (
  'name' => 'John',
  'surname' => 'Smith',
  'company' => 'Redis',
  'age' => '29',
)
*/

Connect to a Redis cluster

To connect to a Redis cluster, specify one or more of the nodes in the clusterNodes parameter and set 'cluster'=>'redis' in options:

$clusterNodes = [
    'tcp://127.0.0.1:30001', // Node 1
    'tcp://127.0.0.1:30002', // Node 2
    'tcp://127.0.0.1:30003', // Node 3
];
$options    = ['cluster' => 'redis'];

// Create a Predis client for the cluster
$rc = new PredisClient($clusterNodes, $options);

echo $rc->cluster('nodes'), PHP_EOL;
/* >>>
d8773e888e92d015b7c52fc66798fd6815afefec 127.0.0.1:30004@40004 slave cde97d1f7dce13e9253ace5cafd3fb0aa67cda63 0 1730713764217 1 connected
58fe1346de4c425d60db24e9b153926fbde0d174 127.0.0.1:30002@40002 master - 0 1730713763361 2 connected 5461-10922
015ecc8148a05377dda22f19921d16efcdd6d678 127.0.0.1:30006@40006 slave c019b75d8b52e83e7e52724eccc716ac553f71d6 0 1730713764218 3 connected
aca365963a72642e6ae0c9503aabf3be5c260806 127.0.0.1:30005@40005 slave 58fe1346de4c425d60db24e9b153926fbde0d174 0 1730713763363 2 connected
c019b75d8b52e83e7e52724eccc716ac553f71d6 127.0.0.1:30003@40003 myself,master - 0 1730713764000 3 connected 10923-16383
cde97d1f7dce13e9253ace5cafd3fb0aa67cda63 127.0.0.1:30001@40001 master - 0 1730713764113 1 connected 0-5460
*/

echo $rc->set('foo', 'bar'), PHP_EOL;
// >>> OK
echo $rc->get('foo'), PHP_EOL;
// >>> bar

Connect to your production Redis with TLS

When you deploy your application, use TLS and follow the Redis security guidelines.

Use the following commands to generate the client certificate and private key:

openssl genrsa -out redis_user_private.key 2048
openssl req -new -key redis_user_private.key -out redis_user.csr
openssl x509 -req -days 365 -in redis_user.csr -signkey redis_user_private.key -out redis_user.crt

If you have the Redis source folder available, you can also generate the certificate and private key with these commands:

./utils/gen-test-certs.sh
./src/redis-server --tls-port 6380 --port 0 --tls-cert-file ./tests/tls/redis.crt --tls-key-file ./tests/tls/redis.key --tls-ca-cert-file ./tests/tls/ca.crt

Pass this information during connection using the ssl section of options:

$options = [
    'scheme' => 'tls', // Use 'tls' for SSL connections
    'host' => '127.0.0.1', // Redis server hostname
    'port' => 6379, // Redis server port
    'username' => 'default', // Redis username
    'password' => '', // Redis password
    'options' => [
        'ssl' => [
            'verify_peer' => true, // Verify the server's SSL certificate
            'cafile' => './redis_ca.pem', // Path to CA certificate
            'local_cert' => './redis_user.crt', // Path to client certificate
            'local_pk' => './redis_user_private.key', // Path to client private key
        ],
    ],
];

$tlsConnection = new PredisClient($options);

echo $tlsConnection->set('foo', 'bar'), PHP_EOL;
// >>> OK
echo $tlsConnection->get('foo'), PHP_EOL;
// >>> bar

Example: Indexing and querying JSON documents

This example shows how to index and query Redis JSON data using predis.

Make sure that you have Redis Stack and predis installed, as described in the Install section above.

Start by importing dependencies:

<?php

require 'vendor/autoload.php';

use Predis\Client as PredisClient;

use Predis\Command\Argument\Search\AggregateArguments;
use Predis\Command\Argument\Search\CreateArguments;
use Predis\Command\Argument\Search\SearchArguments;
use Predis\Command\Argument\Search\SchemaFields\NumericField;
use Predis\Command\Argument\Search\SchemaFields\TextField;
use Predis\Command\Argument\Search\SchemaFields\TagField;
use Predis\Command\Argument\Search\SchemaFields\VectorField;

Connect to the Redis server:

$r = new PredisClient([
                'scheme'   => 'tcp',
                'host'     => '127.0.0.1',
                'port'     => 6379,
                'password' => '',
                'database' => 0,
            ]);

Create some test data to add to the database:

$user1 = json_encode([
    'name' => 'Paul John',
    'email' => 'paul.john@example.com',
    'age' => 42,
    'city' => 'London',
], JSON_THROW_ON_ERROR);

$user2 = json_encode([
    'name' => 'Eden Zamir',
    'email' => 'eden.zamir@example.com',
    'age' => 29,
    'city' => 'Tel Aviv',
], JSON_THROW_ON_ERROR);

$user3 = json_encode([
    'name' => 'Paul Zamir',
    'email' => 'paul.zamir@example.com',
    'age' => 35,
    'city' => 'Tel Aviv',
], JSON_THROW_ON_ERROR);

Create an index. In this example, only JSON documents with the key prefix user: are indexed. For more information, see Query syntax.

$schema = [
    new TextField('$.name', 'name'),
    new TagField('$.city', 'city'),
    new NumericField('$.age', "age"),
];

try {
$r->ftCreate("idx:users", $schema,
    (new CreateArguments())
        ->on('JSON')
        ->prefix(["user:"]));
}
catch (Exception $e) {
    echo $e->getMessage(), PHP_EOL;
}

Add the three sets of user data to the database as JSON objects. If you use keys with the user: prefix then Redis will index the objects automatically as you add them:

$r->jsonset('user:1', '$', $user1);
$r->jsonset('user:2', '$', $user2);
$r->jsonset('user:3', '$', $user3);

You can now use the index to search the JSON objects. The query below searches for objects that have the text "Paul" in any field and have an age value in the range 30 to 40:

$res = $r->ftSearch("idx:users", "Paul @age:[30 40]");
echo json_encode($res), PHP_EOL;
// >>> [1,"user:3",["$","{\"name\":\"Paul Zamir\",\"email\":\"paul.zamir@example.com\",\"age\":35,\"city\":\"London\"}"]]

Specify query options to return only the city field:

$arguments = new SearchArguments();
$arguments->addReturn(3, '$.city', true, 'thecity');
$arguments->dialect(2);
$arguments->limit(0, 5);

$res = $r->ftSearch("idx:users", "Paul", $arguments);

echo json_encode($res), PHP_EOL;
// >>> [2,"user:1",["thecity","London"],"user:3",["thecity","Tel Aviv"]]

Use an aggregation query to count all users in each city.

$ftAggregateArguments = (new AggregateArguments())
->groupBy('@city')
->reduce('COUNT', true, 'count');

$res = $r->ftAggregate('idx:users', '*', $ftAggregateArguments);
echo json_encode($res), PHP_EOL;
// >>> [2,["city","London","count","1"],["city","Tel Aviv","count","2"]]

See the Redis query engine docs for a full description of all query features with examples.

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