title: Rake db:migrate table already exist
body: <p>I don't understand why this is happening. I have the following migration:</p>
  
  <pre><code>def self.up
    create_table :leakages do |t|
      t.integer :feature_id
      t.integer :project_id
      t.float :total
      t.date :apt_date
    end
    add_index :leakages, [:feature_id, :apt_date]
  end
  </code></pre>
  
  <p>When I run it for the first time it runs properly, but when I run the migration again then an error is thrown saying <code>leakages</code> table already exist. Why is this error occurring? I am using the mysql2 gem.</p>