I've a table, which describes work slices of a business working calendar: (date format is 24 hours format)
PK | STARTDATE | ENDDATE
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1 | 2012/07/21 02:00 | 2012/07/21 04:00
2 | 2012/07/21 03:00 | 2012/07/21 10:00
3 | 2012/07/21 06:00 | 2012/07/21 17:00
4 | 2012/07/21 18:00 | 2012/07/21 19:00
Now, I like to merge the date ranges (within a given start and end date) like this:
PK | STARTDATE | ENDDATE
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1 | 2012/07/21 02:00 | 2012/07/21 17:00
2 | 2012/07/21 18:00 | 2012/07/21 19:00
Is there a way to do this with SQL97 standard? If so, what is with other operations (e.g. if I want to to an invered merge, the result should be
PK | STARTDATE | ENDDATE
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1 | 2012/07/21 00:00 | 2012/07/21 02:00
2 | 2012/07/21 19:00 | 2012/07/22 00:00