Question

I am facing a challenge with a SQL query.
Basically I would like to retrieve the registers which present a [Start] later than their respective [Outgoing tasks].

The table looks like this:

Main Project    Main Link    Name         Start            Outgoing tasks
A               1            A1           02.01.2012       A2   
A               1            A2           01.01.2012       A3

…

The query I wrote is this one:

SELECT [Name], [Start], [Outgoing tasks] 
FROM [Sheet1$] 
WHERE [Main project] = 'A' 
AND [Main link] = '1' 
AND [Outgoing tasks] IS NOT NULL 
AND [Start] > (SELECT [Start] 
        FROM [Sheet1$] 
        WHERE [Main project] = 'A' 
        AND [Main link] = '1' 
        AND [Name] =  [Outgoing tasks])

It doesn’t return any error, however it simply doesn’t bring the expected results.

Do you guys know what might be wrong?
Any support is very appreciated!!!

Further info:

This table comes from a MS Project like application. So we have a milestone, its data, successor and predecessor. What I actually need is a list of milestones which have a start date later than its successor (Which is an error in the project management perspective). So if A1.Start > A2.Start, then i should appear in the results. Let me know if you need any further detail.

Answer 1

Try

 select t1.* from [$Sheet1] t1
      inner join [$Sheet1] t2
           on t1.[main project] = t2.[main project]
           and t1.[main link] = t2.[main link]
           and t1.[outgoing tasks] = t2.name
           and t1.start>t2.start