title: ALTER TABLE statement conflicted with the FOREIGN KEY SAME TABLE constraint
body: <p>I like to know if it's possible to create a self refering constraint using an ALTER TABLE statement. (tsql SQL Server 2012)</p>
  
  <p>expected I have a table with just a Primary Key called ID and column called parent_id</p>
  
  <p>I want to do something like this:</p>
  
  <pre><code>ALTER TABLE myTable
  ADD CONSTRAINT FK_myTablemyTable
  FOREIGN KEY (parent_Id)
  REFERENCES myTable(Id)
  </code></pre>
  
  <p>but I just get the error:</p>
  
  <p>The ALTER TABLE statement conflicted with the FOREIGN KEY SAME TABLE constraint</p>
  
  <p>Is there an alternative way to get the statement working, or do you have to recreate the whole table in this case ?</p>
  
  <p>Hope somebody is able to help</p>
  
  <p>Cheers</p>