Learn about composition reference types

A reference type with a reference strength of composition means that the child element is really a part of the parent and does not exist without the parent. If you delete a parent element that has a child element that is compositionally referenced, you delete the child element also.

Effect of a deleted parent element on elements with a composition reference type

Example

Use a composition reference when the two objects in the relationship are considered one item. For example, a meter might be composed of two sensors, and so you would use a composition reference between the Meter element and each of its two child Sensor elements. When you delete the Meter element, the child Sensor elements are also automatically deleted.