How to Create a Batch Apex in Salesforce

Batch Apex is a powerful tool in Salesforce that allows developers to process large volumes of data asynchronously. This article will provide a comprehensive guide on creating a batch Apex class, including its syntax, invocation, and best practices.

Implementing the Database.Batchable Interface

To create a batch Apex class, you must implement the Database.Batchable interface provided by Salesforce. This interface requires you to include three methods: start, execute, and finish.

The start Method

The start method is used to collect the records or objects that will be processed by the batch job. It is called once at the beginning of the job and returns either a Database.QueryLocator object or an Iterable containing the records or objects. The QueryLocator object allows you to bypass the governor limit for the total number of records retrieved by SOQL queries, while the Iterable enforces the limit.

The execute Method

The execute method performs the actual processing for each batch of data passed to it. The default batch size is 200 records, and the batches are not guaranteed to execute in the order they are received from the start method. This method takes a reference to the Database.BatchableContext object and a list of sObjects or parameterized types.

The finish Method

The finish method is used to execute post-processing operations after all batches are processed. It is called once at the end of the job. You can use this method for tasks like sending emails or performing any necessary cleanup.

Invoking a Batch Class

To invoke a batch class, instantiate it and then call Database.executeBatch with the instance. You can also optionally pass a second scope parameter to specify the number of records that should be passed into the execute method for each batch.

Monitoring and Managing Batch Jobs

To monitor or stop the execution of a batch Apex job, you can go to Setup, enter “Apex Jobs” in the Quick Find box, and select “Apex Jobs”. From there, you can view the status of your batch jobs and take appropriate actions.

Best Practices for Batch Apex

To ensure efficient and reliable batch Apex processing, follow these best practices:

• Use Batch Apex only when you have more than one batch of records to process.
• Tune any SOQL queries used in your batch Apex code to minimize execution time.
• Minimize the number of asynchronous requests created to reduce the chance of delays.
• Use extreme caution when invoking batch jobs from triggers to avoid exceeding the batch job limit.

References

• Apex Developer Guide: Batch Apex
• Apex Developer Guide: Using Batch Apex
• Feed Item Detail | Salesforce Trailblazer Community

FAQs

What is Batch Apex?

Batch Apex is a powerful tool in Salesforce that allows developers to process large volumes of data asynchronously, making it suitable for tasks that require extensive processing without hindering the performance of the Salesforce platform.

When should I use Batch Apex?

Batch Apex should be used when you need to process a large number of records (typically more than 200) and the processing can be done asynchronously. This is especially useful for tasks that are computationally intensive or that would take a long time to complete if run synchronously.

How do I create a Batch Apex class?

To create a Batch Apex class, you must implement the Database.Batchable interface, which requires you to define three methods: start, execute, and finish. The start method returns the records to be processed, the execute method performs the processing on each batch of records, and the finish method performs any necessary post-processing.

How do I invoke a Batch Apex class?

To invoke a Batch Apex class, instantiate it and then call Database.executeBatch with the instance. You can also optionally pass a second scope parameter to specify the number of records that should be passed into the execute method for each batch.

How can I monitor and manage Batch Apex jobs?

You can monitor and manage Batch Apex jobs in the Apex Jobs tab in Salesforce Setup. This tab allows you to view the status of your batch jobs, stop running jobs, and view the results of completed jobs.

What are some best practices for using Batch Apex?

Some best practices for using Batch Apex include:
– Use Batch Apex only when necessary, as it can consume more resources than synchronous code.
– Tune any SOQL queries used in your batch Apex code to minimize execution time.
– Minimize the number of asynchronous requests created to reduce the chance of delays.
– Use extreme caution when invoking batch jobs from triggers to avoid exceeding the batch job limit.

What are the limitations of Batch Apex?

Batch Apex has some limitations, including:
– The maximum number of records that can be processed in a single batch is 2000.
– The maximum number of batches that can be processed in a single job is 100.
– Batch Apex jobs can only run for a maximum of 12 hours.

Where can I learn more about Batch Apex?

You can learn more about Batch Apex from the following resources:
– Apex Developer Guide: Batch Apex(https://developer.salesforce.com/docs/atlas.en-us.apexcode.meta/apexcode/apex_batch_interface.htm)
– Apex Developer Guide: Using Batch Apex(https://trailhead.salesforce.com/content/learn/modules/asynchronous_apex/async_apex_batch)
– Batch Apex Trailhead module(https://trailhead.salesforce.com/modules/asynchronous_apex/units/async_apex_batch)