Salesforce report relationships

Question

I have noticed there are 3 ways to get data across related objects into reports.

1.) Custom Report Types - you can create report types with a Parent Object and traverse down related Objects.

2.) Joined Reports - You can create a report with different objects into one reports

3.) Add fields to the layout of a custom report type through traversing related objects in the 'add fields related via lookup' on the side of the custom report tpye.

My Question is, why are there 3 different ways to get data into a report of related objects? And how do I know which one to use?

Answer 1

1. Custom reports type objects only go down an object hierarchy. That is where an object A is related to multiple object Bs which is related to multiple object Cs. You have to use existing relationships and you can decide if you want to only see parent records if they have no children. Most of these types are created for you if you allow reporting on the object.

2. Joined reports are for when there is not already a specific join between two objects but they have a related parent object in common. This would like show all object X and object Y owned by the same person.

3. Additional Lookup fields are similar to #1 but allow you to grab more fields from other objects for the report. Say you have object A with multiple object Bs, and object D with multiple object Bs. You can have a report where you have A with Bs and pull in some fields from object D via the lookup from object B.

The other commentary on why there are multiple ways that do not seem very connected is that the product is an evolution. Joined reports and report types were released at different times, which can contribute to why they feel disjointed.