How to Identify Records with Overlapping Dates

[DudeGenius]

I need to be able to systematically identify any instance where there are
overlapping date ranges in a data set. I need to pull records like those
listed below out of a larger data set. I previously posted a question similar
to this and was advised to pull the same table in a query, match on Member
Number, and qualify that the product code from TableA did not match product
code in TableA_1 where the Begin Date TableA was < Term date TableA_1 and
TableA_1 Begin Date < TableA End Date. Which worked great for me finding
overlapping records where the product was different, but now I also need to
find them when the product is the same

ProductCode MemberNumber Begin Date End Date
PFFS 123456789A 20090101 20091231
PFFS 123456789A 20081201 29991231

Thanks for you help

 

[Daryl S]

You can remove the criteria that the products are different.

If there is a primary key field on the table, then you would want those to
not match between TableA and TableA1, and it could be the product was the
closest option to use. This would be to avoid the SAME record to match the
from TableA to TableA_1, but with your < criteria, you should be fine.

 

[KARL DEWEY]

This select record that has another record overlapping it --
SELECT ProductCode, MemberNumber, [Begin Date], [End Date]
FROM TableA
WHERE TableA.[End Date] > (SELECT TOP 1 [TableA_1].[Begin Date] FROM TableA
AS TableA_1 WHERE [TableA_1].[Begin Date] >= [TableA].[Begin Date] ORDER BY
[TableA_1].[Begin Date] DESC);