text: """empty message
  
  Revision ID: 30e6fbf01833
  Revises: 1ba5ea3134a7
  Create Date: 2021-05-25 22:45:17.387052
  
  """
  from alembic import op
  import sqlalchemy as sa
  
  
  # revision identifiers, used by Alembic.
  revision = '30e6fbf01833'
  down_revision = '1ba5ea3134a7'
  branch_labels = None
  depends_on = None
  
  
  def upgrade():
      with op.batch_alter_table('activities') as batch_op:
          batch_op.add_column(sa.Column('ref_url', sa.String(length=2048), nullable=True))
          batch_op.alter_column('user_id', nullable=True)
          batch_op.alter_column('project_id', nullable=True)
  
  
  def downgrade():
      with op.batch_alter_table('activities') as batch_op:
          batch_op.alter_column('user_id', nullable=False)
          batch_op.alter_column('project_id', nullable=False)
          batch_op.drop_column('ref_url')
  