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I am trying to identify the start and stop of a particular incident- these are indicated by the unique values 0,1,2,3,4,5,6.

0 represents no incident- therefore in order to identify when an incident starts and stops and only retrieve these data records (i.e. incident 1) I would like to know how to query or determine when the value in the incident field changes from a 0 to a 1 (i.e. the start) and query when the value changes from a 1 to a 0 i.e. the finish. I only want to compare these changes between adjacent records i.e. those either side of a record.

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Because--at least in its current form--this is really a data analysis question, having nothing essential to do with spatial data, posting it here could unnecessarily narrow the pool of potential respondents. You might be better off migrating it to a more general site, perhaps SO. Regardless, providing more information about the data structure-especially concerning how time is represented--will reduce the need for us to guess about it and improve your chances of getting a solution that works for you. – whuber Apr 16 '11 at 17:17
How is your data stored? Point, Line, Poly, Raster? Are you wanting to (as mentioned by ujjwalesri) determine when a particular field has change values from 1 to 0 (time-based), or where adjacent features have changed from 1 to 0 (such as where a road segment changes from dirt to pavement)? Your question leaves lots of other questions for contributors to try and figure out before answering the question correctly. – RyanDalton Jun 15 '11 at 20:48

Like pointed out by others, the data structure information is missing. I am not sure if you want to fire a custom action on the value change.

Assuming you have a database, you can think of writing a trigger for every update in that field. Check if the update changes the value to 1 or back to 0. Based on the final value, you can decide the course of action.

But I am not sure if you can launch external programs from within SQL environment.

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You haven't described your data structure very clearly but to get started with you can perofrm a select by attribute.

It sounds like you may have some more sophisticated data structure and may want to time analize these data. For which tracking analyst would be a good solution for you.

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