Development with the Force.com Platform: Building Business Applications in the Cloud, Third Edition

Semi-Join and Anti-Join

In Chapter 4, “Business Logic,” you learned the two ways related objects can be included in SOQL: parent-to-child and child-to-parent queries. Semi-join and anti-join queries enhance the functionality of both queries, and add the ability to make child-to-child queries. In general, they allow records from one object to be filtered by a subquery against another object.

For example, suppose you need a list of all Account records that have at least one Project record in a yellow status. To make sure you have a valid test case, edit one of the Project records in the native user interface to set it to a yellow status. Try to write a query to return its Account, with Account as the base object.

You can’t do this without using ...