Return values from Left Table Only Once

This is my table structure and a sample query. However, my query returns these results:

ID   event1  Exists
1    cycle   No
1    cycle   Yes
2    run     Yes
3    walk    No

As you can see ID 1 is returned twice, a yes and a no value. I only want each item from event1 returned 1 time in my query. Desired output is:

ID   event1  Exists
1    cycle   Yes
2    run     Yes
3    walk    No

Here is sample table structure and my query (which please feel free to completely re-write), what must be altered in order to return my desired result set?

create table #robschneider
(
  ID int IDENTITY(1,1) PRIMARY KEY
  ,event1 varchar(100)
  ,uuid int
)
create table #bigponyhorses
(
  ID int IDENTITY(1,1) PRIMARY KEY
  ,uuid int
  ,empid varchar(10)
)
Insert Into #robschneider Values ('cycle', '1'), ('run', '2'), ('walk', '3')
Insert Into #bigponyhorses VALUES ('1','mn12'), ('2','mn12'), ('3', 'cr23'), ('1', 'bb11')

Declare @empid varchar(10)
Set @empid = 'mn12'

select
DISTINCT
[rs].[ID],
[rs].[event1],
case 
  when [bph].[empid] = @empid AND [bph].[uuid] is not null then 'Yes' else 'No' 
end as [Exists]
from #robschneider rs
LEFT join #bigponyhorses bph
on [rs].[uuid]=[bph].[uuid]

If it exists, I want a yes returned, if it does not exist I want a no returned.

This could be solved with an EXISTS subquery

select
    rs.ID,
    rs.event1,
    [Exists] =
        case when exists
                ( select *
                  from #bigponyhorses as bph
                  where rs.uuid = bph.uuid
                    and bph.empid = @empid
                ) 
            then 'Yes' else 'No'
        end
from 
    #robschneider as rs ;

or with OUTER APPLY operator:

select
    rs.ID,
    rs.event1,
    [Exists] = coalesce(b.result, 'No') 
from 
    #robschneider as rs
  outer apply 
    ( select top (1) result = 'Yes'
      from #bigponyhorses as bph
      where rs.uuid = bph.uuid
        and bph.empid = @empid
    ) as b ;

The TOP 1 is needed when using OUTER APPLY to make sure you get in the result one row for each #robschneider, even if there are 2 or more matching rows in the #bigponyhorses table. If there is a UNIQUE constraint on #bigponyhorses (uuid, empid), then it's not needed.

StackExchange Database Administrators Q#129448, answer score: 2