Adding Constraints Using Expressions

When entities have defined properties, it enables you to create more focused queries because the values of those properties will vary by entity. You could have an entity type of "person" and properties for that entity type could include gender, age, or parental status. These properties would make it possible for you to run queries that look only for males, or for people in a certain age group, or for people who have at least one child. There are endless reasons for wanting to run a targeted query, and incorporating expressions that are based on properties into your query allows you to do that.