Q:

MySQL check if two date range overlap with input

I need to check if two dates over lap with another two dates in my database.
My database looks like this
+----+--------------+------------+------------+
| id | code         | StartDate  | EndDate    |
+----+--------------+------------+------------+
|  1 | KUVX-21-40   | 2013-10-23 | 2013-11-22 |
|  2 | UEXA286-1273 | 2013-10-30 | 2013-11-29 |
|  3 | UAJFAU-2817  | 2013-10-21 | 2013-11-20 |
|  4 | KUVX-21-40   | 2013-10-30 | 2013-11-29 |
+----+--------------+------------+------------+

In my query i specify the scope: A start date and an enddate
Lets asign them as follows:
ScopeStartDate = "2013-10-1"
ScopeEndDate = "2013-11-26"

Above should return me all of the records, since the all overlapse the timespan.
However I cannot get a query working :/
I've tried the following query with no luck:
WHERE
(
    (StartDate < ScopeStartDate AND StartDate > ScopeStartDate)
    OR
    (StartDate > ScopeStartDate  AND EndDate < ScopeEndDate )
)

This returns me two results: 
1 and 3
what am I doing wrong?

A:

I believe the following condition matches every possible overlapping case.
WHERE
(
    (ScopeStartDate <= EndDate AND ScopeEndDate >= StartDate)

)

except if you declare illogic timespans (for example, those which end before starting)

