title: What is the reason behind a Full outer Join resulting in more rows than either parent data set?
body: <p>I'm working with two sets of data that I am trying to combine via a Join command (not a Union).</p>
  
  <p>I don't think I understand the basics of joining. I used a Full Outer Join as follows:</p>
  
  <pre><code>    Select
        Table1.col1,
        Table1.col2, 
        Table1.date1,
        Table2.col1,
        Table2.col2,
        Table2.date2
     From Table1 full outer join 
          Table2 On Table1.date1 = Table2.date2
  </code></pre>
  
  <p>The final combined dataset had a total number of rows greater than the sum of rows in Table1 and Table2. </p>
  
  <p>I'm trying to understand why this would happen. </p>
  
  <p>I was under the impression that (# rows in CombinedTable) = (# rows in Table1) + (# rows in Table2). </p>
  
  <p>Why does this occur? How can I fix this?</p>