if we are using oracle as a data source we can use TODD 
(fornt end for oracle) to test the report . Take the SQL 
statement from the SQL editor of Query panel and run the 
query in the Todd .

In BO intially to check the report, we go for Integrity 
check . One button is there to check the integrity,parse 
error, joins,loops and soon.
The second stage of testing involves testing the SQL query 
of the report if it uses free hand SQL else we need to test 
the universe which the report is using.

If we use the query of the report in the TOAD it would show 
the same result. And the integrity check is only for 
testing the universe and not for the report.
We would check the report by manually. As the report having 
n number of rows we would not check for all and check it 
randomly. This is the way to test the report.

To test the report the simply write the SQL query and test
it in the database, if copy and paste the SQL generated by
the BO in Report Panel and fires it in TODD then it gives
the same result. So to test report we need to manually write
the SQL and then test it in the database and compare whether
the result is correct or not. 
For your kind information, Integrity Check is not used for
Universe testing and not for Report testing.

To test a report we have to match the reports value with
actual value in database.
We need to follow following steps:
1. Note down the value displaying in report for particular
business object.
2. Calculate the value from Back end by using query analyzer
or Toad.
3. Match both values.

LET ME CORRECT IF I AM WRONG.