PHP Redis::exec() Method: Usage and Examples

Executes commands previously queued with multi or pipeline and returns their results.

The objective is to understand the behavior and operational limits, not only the method name.

What It Does

Executes commands previously queued with multi or pipeline and returns their results.

Syntax and Return Value

Redis::exec(...)

The return value and exceptional cases depend on the call described here: MULTI does not automatically roll back earlier queued commands when another command fails.

Requirements: install and enable the corresponding PHP driver or extension and configure the service before running the examples.

Example 1: Basic Use

Requires the phpredis extension and a running Redis server. Keys use a guide-specific prefix; clean up example keys after experimenting.

<?php
$redis = new Redis();
$redis->connect(getenv('REDIS_HOST') ?: '127.0.0.1', (int) (getenv('REDIS_PORT') ?: 6379), 2.0);
$redis->multi();
$redis->set('guide:exec:1','draft');
$redis->incr('guide:exec:1:secondary');
$results = $redis->exec();
echo json_encode($results);

Example 2: A Second Scenario

Requires the phpredis extension and a running Redis server. Keys use a guide-specific prefix; clean up example keys after experimenting.

<?php
$redis = new Redis();
$redis->connect(getenv('REDIS_HOST') ?: '127.0.0.1', (int) (getenv('REDIS_PORT') ?: 6379), 2.0);
$redis->multi();
$redis->set('guide:exec:2','review');
$redis->incr('guide:exec:2:secondary');
$results = $redis->exec();
echo json_encode($results);

Example 3: Practical Checks

Requires the phpredis extension and a running Redis server. Keys use a guide-specific prefix; clean up example keys after experimenting.

<?php
$redis = new Redis();
$redis->connect(getenv('REDIS_HOST') ?: '127.0.0.1', (int) (getenv('REDIS_PORT') ?: 6379), 2.0);
$redis->multi();
$redis->set('guide:exec:3','published');
$redis->incr('guide:exec:3:secondary');
$results = $redis->exec();
echo json_encode($results);

Important Behavior and Edge Cases

MULTI does not automatically roll back earlier queued commands when another command fails.

For production use, also account for error handling, data validation, resource limits and environment-specific driver behavior.

Comparison with Related Approaches

Common Beginner Mistakes

Key Takeaways

• Executes commands previously queued with multi or pipeline and returns their results.
• MULTI does not automatically roll back earlier queued commands when another command fails.
• multi queues commands atomically on execution; pipeline only batches network traffic.

Choose this API or pattern when its exact semantics match your task, and verify the result against the database driver and runtime used by your application.