By UATeam in platform events —

Query Platform Events in Salesforce: A Complete Guide

Platform Events in Salesforce are a key feature for implementing event-driven architectures. They allow systems to communicate asynchronously, enabling seamless integration and real-time data sharing. While publishing and subscribing to Platform Events are common use cases, querying them is another crucial aspect for debugging and monitoring. This article explains how to query Platform Events in Salesforce, the limitations, and best practices for managing event data.

What Are Platform Events in Salesforce?

Platform Events are custom objects designed for event-driven communication in Salesforce. They enable you to:

  • Publish events to communicate between Salesforce and external systems.
  • Subscribe to events using Apex triggers, Process Builder, or external platforms through CometD.

Unlike traditional objects, Platform Events are ephemeral and designed for real-time data flow.

Can You Query Platform Events?

Yes, Platform Events can be queried using SOQL (Salesforce Object Query Language), but with limitations:

  1. Retention Period: Platform Event records are stored temporarily, typically for 24 hours.
  2. Read-Only Access: Platform Events are immutable, meaning you can query them but cannot update or delete them.
  3. Query Limits: You can use SOQL to retrieve event records only if your Salesforce org has Event Retention for Platform Events enabled.

Steps to Query Platform Events in Salesforce

1. Create a Platform Event

Before querying, ensure you have a Platform Event defined in your org. Here’s how:

  1. Go to Setup.
  2. Search for Platform Events in the Quick Find box.
  3. Click New Platform Event.
  4. Define fields as needed.

Example Platform Event: Order_Status__e

  • Fields:
    • Order_ID__c (Text)
    • Status__c (Picklist)

2. Query Platform Events Using SOQL

Once events are published, you can query them using the EventBusSubscriber object. Here's an example query:

SELECT CreatedDate, ReplayId, Order_ID__c, Status__c
FROM Order_Status__e
WHERE Status__c = 'Shipped'
ORDER BY CreatedDate DESC

Key Fields:

  • ReplayId: A unique identifier for the event instance.
  • CreatedDate: Timestamp when the event was created.

3. Use Developer Console to Query Events

To query Platform Events in Salesforce:

  1. Open the Developer Console.
  2. Go to Query Editor.
  3. Enter your SOQL query:SELECT CreatedDate, ReplayId, Order_ID__c, Status__c FROM Order_Status__e
  4. Click Execute.

4. Query Events via REST API

You can also query Platform Events programmatically using the REST API.

Example: Query with REST API

Endpoint:

/services/data/v57.0/query/?q=SELECT+CreatedDate,ReplayId,Order_ID__c,Status__c+FROM+Order_Status__e

Use tools like Postman or write custom scripts in your application to query events.

Monitoring Platform Events

Event Monitoring Dashboard

Use the Event Monitoring Dashboard in Salesforce to track published and subscribed Platform Events. This helps ensure system health and debug issues.

Best Practices for Querying Platform Events

  1. Enable Event Retention:
    • Ensure your Salesforce org has Event Retention for Platform Events enabled if you need to query events beyond real-time use cases.
  2. Use Replay IDs:
    • Leverage the ReplayId field for retrieving specific events or reprocessing them.
  3. Optimize Queries:
    • Add filters to your queries (e.g., WHERE clauses) to limit data retrieval and improve performance.
  4. Monitor Limits:
    • Be aware of Salesforce’s governor limits on query rows and API calls when working with large volumes of events.
  5. Use External Logging:
    • For long-term analysis, consider exporting event data to external systems (e.g., AWS, Azure, or Splunk).

Limitations of Querying Platform Events

  1. Short Retention Period:
    • Event records are stored for a limited time (24 hours by default).
  2. Limited Query Capabilities:
    • Platform Events do not support complex relationships like parent-child queries.
  3. Read-Only Nature:
    • You cannot modify or delete queried event data.

Conclusion

Querying Platform Events in Salesforce is a valuable tool for debugging and monitoring event-driven architectures. By leveraging SOQL and Salesforce APIs, you can retrieve and analyze event data effectively. Always follow best practices to optimize performance and ensure compliance with Salesforce’s query limits and retention policies.