Microsoft Access Database: Building Access Reports with Sub-Reports
In a nutshell, a sub-report is a report embedded into another report and normally has a relationship to the main (parent) report.
In essence, you can have more than one sub-report with the Microsoft Access database object linking to the parent report or even as a nested sub-sub-report!
Sub-reports however do not have to be related in any way and therefore each can be a stand-alone Microsoft Access report in another report, which has some advantages encapsulating different levels of reporting in one.
Consider also having a chart, a summary table with detailed lists which could all be stored in one report (as the shell) but built as separate (sub)-report objects.
The technical and main difference between sub-reports related to a main report versus a sub-report which is not related at all is driven by three properties one being a Record Source on the main report and a Record Source from the sub-report (having a common field to link by) referring to either the query or SQL statement and is deemed to be Bound. Non related data (i.e. no Record Source) is deemed Unbound.
There are many examples that use a report and sub-report relationship in Microsoft Access but the important aspect is to know your Properties which will give you full control.
Take a look at my eBook on How to Build Access Database Reports which covers the basics to the nesting of reports and other objects highlighting clear instructions and of course those all important Properties!
What About Microsoft Access Forms?
Well, you can also have a sub-form in a form too and it works in exactly the same way as a sub-report. To learn more about Forms, see my eBook on How to Build Access Forms.