title: cannot insert duplicate key row in table with unique index
body: <p>I am debugging a stored procedure which gives me the following error when executed:</p>
  
  <pre><code>2601: Cannot insert duplicate key row in object 'dbo.TABLEXYZ' with unique index 'ABCKEY_PRIMARY'. The duplicate key value is (abc123).
  </code></pre>
  
  <p>There is no data being inserted in dbo.TABLEXYZ through the sproc I am executing, I also looked if there was any trigger which updated dbo.TABLEXYZ, but there was none. Any tips on how to approach debugging a complex sproc? Where else should I look to find the culprit?</p>