Suppose these are our two tables, Person and Person Details, having one to many relationships to each other.
Now first create a report having following simple query for the data set
SELECT Id, [First Name], [Last Name], Email FROM Person
Now create one more report which we would be using as a Subreport with the following query
SELECT Hobby FROM [Person Details] WHERE (Id = @Id)
Now go to our main report, select id column, right click it and select add column to the right.
Drag Subreport control from the toolbox there in the new column added
Next right click it and select Subreport properties
Specify the detail report as Subreport.
For visibility specify the following options (report would be auto expanded and we will have + sign in front of our id column through which we can toggle the visibility of the subreport)
For Parameters specify value for the id to be passed from the main report.
That’s it. We are done J
Hope it is helpful.