old_contents: """Add ranking data to participants table
  
  Revision ID: 451d4bb125cb
  Revises: 49be2190c22d
  Create Date: 2017-11-10 13:57:37.807238+00:00
  
  """
  from alembic import op
  import sqlalchemy as sa
  from sqlalchemy.dialects import mysql
  
  
  # revision identifiers, used by Alembic.
  revision = '451d4bb125cb'
  down_revision = '49be2190c22d'
  branch_labels = None
  depends_on = None
  
  
  def upgrade():
      op.add_column(
          "game_participant",
          sa.Column('mu', mysql.FLOAT(),
                    nullable=True),
      )
      op.add_column(
          "game_participant",
          sa.Column('sigma',
                    mysql.FLOAT(unsigned=True),
                    nullable=True),
      )
      op.add_column(
          "game_participant",
          sa.Column('rank',
                    mysql.SMALLINT(display_width=5),
                    autoincrement=False,
                    nullable=True),
      )
  
  
  def downgrade():
      op.drop_column("game_participant", "mu")
      op.drop_column("game_participant", "sigma")
      op.drop_column("game_participant", "rank")
  
new_contents: """Add ranking data to participants table
  
  Revision ID: 451d4bb125cb
  Revises: 49be2190c22d
  Create Date: 2017-11-10 13:57:37.807238+00:00
  
  """
  from alembic import op
  import sqlalchemy as sa
  from sqlalchemy.dialects import mysql
  
  
  # revision identifiers, used by Alembic.
  revision = '451d4bb125cb'
  down_revision = '49be2190c22d'
  branch_labels = None
  depends_on = None
  
  
  def upgrade():
      op.add_column(
          "game_participant",
          sa.Column('mu', mysql.FLOAT(),
                    nullable=True),
      )
      op.add_column(
          "game_participant",
          sa.Column('sigma',
                    mysql.FLOAT(unsigned=True),
                    nullable=True),
      )
      op.add_column(
          "game_participant",
          sa.Column('leaderboard_rank',
                    mysql.SMALLINT(display_width=5),
                    autoincrement=False,
                    nullable=True),
      )
  
  
  def downgrade():
      op.drop_column("game_participant", "mu")
      op.drop_column("game_participant", "sigma")
      op.drop_column("game_participant", "leaderboard_rank")
  
subject: Rename rank field to avoid column name clash