old_contents: """Add organizations-users association table
  
  Revision ID: 4fdf1059c4ba
  Revises: 393a48ab5fc7
  Create Date: 2012-09-02 12:37:11.785052
  """
  
  # revision identifiers, used by Alembic.
  revision = '4fdf1059c4ba'
  down_revision = '393a48ab5fc7'
  
  
  from alembic import op
  import sqlalchemy as sa
  
  
  def upgrade():
      op.create_table('memberships',
          sa.Column('id', sa.Integer(), nullable=False),
          sa.Column('organization_id', sa.Integer(), nullable=True),
          sa.Column('user_id', sa.Integer(), nullable=True),
          sa.ForeignKeyConstraint(['organization_id'], ['organizations.id'], ),
          sa.ForeignKeyConstraint(['user_id'], ['users.id'], ),
          sa.PrimaryKeyConstraint('id')
      )
  
  
  def downgrade():
      op.drop_table('memberships')
  
new_contents: """Add organizations-users association table
  
  Revision ID: 4fdf1059c4ba
  Revises: 393a48ab5fc7
  Create Date: 2012-09-02 12:37:11.785052
  """
  
  # revision identifiers, used by Alembic.
  revision = '4fdf1059c4ba'
  down_revision = '393a48ab5fc7'
  
  
  from alembic import op
  import sqlalchemy as sa
  
  
  def upgrade():
      op.create_table('memberships',
          sa.Column('id', sa.Integer(), nullable=False),
          sa.Column('organization_id', sa.Integer(), nullable=True),
          sa.Column('user_id', sa.Integer(), nullable=True),
          sa.ForeignKeyConstraint(
              ['organization_id'], ['organizations.id'], ondelete='CASCADE'
          ),
          sa.ForeignKeyConstraint(
              ['user_id'], ['users.id'], ondelete='CASCADE'
          ),
          sa.PrimaryKeyConstraint('id')
      )
  
  
  def downgrade():
      op.drop_table('memberships')
  
subject: Fix memebership table creation migration