Re: Overlapping dates Issue

If there is no range (just single dates), that's easy. Just count the rows:

SELECT COUNT(*)
  FROM Company_relationship
 WHERE effective_date  = ?
    OR expiration_date = ?
[download]

If effective_date and expiration_date are begin and end dates, I bet you can do:

SELECT COUNT(*)
  FROM Company_relationship
 WHERE effective_date <= ?
   AND expiration_date > ?
[download]

Both return one record with one field. If it's 0, proceed. Otherwise, you have an overlap.

Comment on Re: Overlapping dates Issue Select or Download Code

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Re^2: Overlapping dates Issue by data67 (Monk) on Mar 22, 2006 at 17:11 UTC
Actually, yes there is a concept here of overlapping. I used your query and it did not work for all cases. I went on Oracles website and found the answer there. Here is the link: http://asktom.oracle.com/pls/ask/f?p=4950:8:15236886734525876868::NO::F4950_P8_DISPLAYID,F4950_P8_CRITERIA:4921012347969, and we said... Do you need to be concerned with all overlaps? Eg: in database you have 01-jan-2001 07-jan-2001 you are given as inputs: `15-dec-2000 15-jan-2001 - wider then database 15-dec-2000 04-jan-2001 - overlaps but not contained within 04-jan-2001 15-jan-2001 - overlaps but not contained within 02-jan-2001 04-jan-2001 - overlaps and contained within` [download] should all four return a "hit"? `select * from t where ( c_beginning between p_beginning and p_ending -- rule 1 OR c_ending between p_beginning and p_ending -- rule 2 OR ( c_beginning < p_beginning and p_ending < c_ending ) ); -- + rule 3` [download] will do that. If you use the following "chart", it depicts all of the possibles and which "rule" in the predicate above will catch them: `............................................. CB CE PB PE -- rule 1 PB PE -- rule 1 PB PE -- rule 2 PB PE -- rule 3 PB PE -- no hit PB PE -- no hit` [download] Thanks, data	[reply] [d/l] [select]

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Re^2: Overlapping dates Issue
by data67 (Monk) on Mar 22, 2006 at 17:11 UTC

http://asktom.oracle.com/pls/ask/f?p=4950:8:15236886734525876868::NO::F4950_P8_DISPLAYID,F4950_P8_CRITERIA:4921012347969,

and we said... Do you need to be concerned with all overlaps? Eg: in database you have

01-jan-2001 07-jan-2001

you are given as inputs:

  15-dec-2000     15-jan-2001   - wider then database
  15-dec-2000     04-jan-2001   - overlaps but not contained within
  04-jan-2001     15-jan-2001   - overlaps but not contained within
  02-jan-2001     04-jan-2001   - overlaps and contained within
[download]

should all four return a "hit"?

select *
  from t
  where ( c_beginning between p_beginning and p_ending      -- rule 1
       OR c_ending between p_beginning and p_ending         -- rule 2
       OR ( c_beginning < p_beginning and p_ending < c_ending ) );  --
+ rule 3
[download]

.............................................
             CB                CE
PB                                     PE     -- rule 1
PB                   PE                       -- rule 1
                     PB                PE     -- rule 2
                  PB     PE                   -- rule 3
PB  PE                                        -- no hit
                                        PB PE -- no hit
[download]

Thanks,
data

[reply]
[d/l]
[select]