title: Error with South when migrating changes to model
body: <p>I have added a foreign key to a user to a model, but when I try to migrate the database using South, I get the following error:</p>
  
  <pre><code>_mysql_exceptions.OperationalError: (1067, "Invalid default value for 'user_id'")
  </code></pre>
  
  <p>South tells me that I may be able to recover from the error by running an SQL command:</p>
  
  <pre><code>! You *might* be able to recover with:   = 
      ALTER TABLE `main_deal` DROP COLUMN `user_id` CASCADE; []
  </code></pre>
  
  <p>I tried to run the SQL command, but I get the following error:</p>
  
  <pre><code>#1091 - Can't DROP 'user_id'; check that column/key exists
  </code></pre>
  
  <p>Do I need to add 'user_id' to my model and set the default value to 1?</p>
  
  <p>Edit:
  Here is the code that I added to my model to cause this to occur:</p>
  
  <pre><code>user = models.ForeignKey(User)
  </code></pre>
  
  <p>Then I migrated the model using South.</p>