SQL Self Join Query Help
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Published on 2010-04-17T10:12:27Z
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2010/04/17
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Hi All,
I'm trying to work out a query that self join itself on a table using the eventnumber. I've never done a self join before.
What i'm trying to query is when a client has started off in a city which is chester to see what city they moved to. But I dont want to be able to see if they started off in another city. I would also like be only see the move once (So i'd only like to see if they went from chester to london rather then chester to london to wales)
The StartTimeDate is the same EndDateTime if they moved to another city.
Data example as follows if they started off in the city chester :-
clientid EventNumber City StartDateTime EndDateTime
1 1 Chester 10/03/2009 11/04/2010 13:00
1 1 Liverpool 11/04/2010 13:00 30/06/2010 16:00
1 1 Wales 30/07/2010 16:00
the result I would like to see is on the 2nd row - so it only shows me liverpool.
Could anyone point in the right direcetion please?
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