title: Left Join Returning Extra Rows T-SQL?
body: <p>I have the following query:</p>
  
  <pre><code>select * from ACADEMIC a
  left join RESIDENCY r on a.PEOPLE_CODE_ID = r.PEOPLE_CODE_ID
  where a.ACADEMIC_TERM='Fall' 
  and r.ACADEMIC_TERM='Fall'
  and a.ACADEMIC_SESSION=''
  and a.ACADEMIC_YEAR = (Select Year(GetDate())) 
  and r.ACADEMIC_YEAR = (Select Year(GetDate()))
  and (CLASS_LEVEL LIKE 'FR%'
       OR a.CLASS_LEVEL LIKE 'SO'
       OR a.CLASS_LEVEL LIKE 'JR'
       OR a.CLASS_LEVEL LIKE 'SR%') 
  and r.RESIDENT_COMMUTER='R'
  </code></pre>
  
  <p>For each person in the database it returns two rows with identical information. Yet, when I do the same query without the left join:</p>
  
  <pre><code>select * from ACADEMIC a
  where a.ACADEMIC_TERM='Fall' 
  and a.ACADEMIC_SESSION=''
  and a.ACADEMIC_YEAR = (Select Year(GetDate())) 
  and (CLASS_LEVEL LIKE 'FR%'
       OR a.CLASS_LEVEL LIKE 'SO'
       OR a.CLASS_LEVEL LIKE 'JR'
       OR a.CLASS_LEVEL LIKE 'SR%') 
       ORDER BY PEOPLE_ID
  </code></pre>
  
  <p>It returns only one row for each person. I'm doing a left join - why is it adding an extra row? Shouldn't it only do that if I add a right join?</p>
  
  <p>(Updated formatting for consistency/readability.)</p>