Question

I have to figure out which swimmers got the same place in the same event. For each pair of such swimmers, i have to display one row showing the event id, the place, and the competitor number of each swimmer involved. example

eventid  place  competitors tied

SWM012  2   1072528 1099641

SWM021  2   1018529 1061698

This is my code so far

select R1.Eventid, R1.Place, R1.Competitornum, R2.Competitornum
from Results R1, Results R2 
where R1.Place = R2.Place
group by R1.Eventid, R1.Place, R1.Competitornum, R2.Competitornum

and this is the output

eventid  Place   competitornum    competitornum

SWM010   1       1121587           1056740

SWM010   1       1121587           1061698

and so on same competitornum for the first column different in the second competitornum column

i just want to know how to get the output like in the above description

Answer 1

First, you likely need to join on the Event ID as well

select R1.Eventid, R1.Place, R1.Competitornum, R2.Competitornum
from Results R1, Results R2 
where R1.Place = R2.Place AND R1.EventId = R2.EventId
group by R1.Eventid, R1.Place, R1.Competitornum, R2.Competitornum

The above query returns the same results as this

select distinct R1.Eventid, R1.Place, R1.Competitornum, R2.Competitornum
from Results R1, Results R2 
where R1.Place = R2.Place AND R1.EventId = R2.EventId

But this will return all unique pairs of ‘ties’. One solution is this

select distinct R1.Eventid, R1.Place, R1.Competitornum, R2.Competitornum
from Results R1, Results R2 
where R1.Place = R2.Place AND R1.EventId = R2.EventId AND R1.Competitornum > R2.Competitornum

This only works for two-way ties, though.