What if you want to create a Batch Apex Job that uses SOQL having aggregate functions like SUM, MAX, and COUNT on top of results grouped by the “GROUP BY” clause? You can’t easily create a Batch job via QueryLocator, as shown below. When working with Batch Apex in Salesforce, you might encounter a scenario where you need to run SOQL queries with aggregate functions like SUM, MAX, or COUNT while grouping results using the GROUP BY clause.

force.com standard and custom objects allow you to define fields with default values. However, there is a major confusion regarding the usage and availability of default values in Apex code.