content: """private messages
  
  Revision ID: d049de007ccf
  Revises: 834b1a697901
  Create Date: 2017-11-12 23:30:28.571784
  
  """
  from alembic import op
  import sqlalchemy as sa
  
  
  # revision identifiers, used by Alembic.
  revision = 'd049de007ccf'
  down_revision = '2b017edaa91f'
  branch_labels = None
  depends_on = None
  
  
  def upgrade():
      # ### commands auto generated by Alembic - please adjust! ###
      op.create_table('message',
      sa.Column('id', sa.Integer(), nullable=False),
      sa.Column('sender_id', sa.Integer(), nullable=False),
      sa.Column('recipient_id', sa.Integer(), nullable=False),
      sa.Column('body', sa.String(length=140), nullable=False),
      sa.Column('timestamp', sa.DateTime(), nullable=False),
      sa.ForeignKeyConstraint(['recipient_id'], ['user.id'], ),
      sa.ForeignKeyConstraint(['sender_id'], ['user.id'], ),
      sa.PrimaryKeyConstraint('id')
      )
  
      with op.batch_alter_table('message', schema=None) as batch_op:
          batch_op.create_index(batch_op.f('ix_message_recipient_id'), ['recipient_id'], unique=False)
          batch_op.create_index(batch_op.f('ix_message_sender_id'), ['sender_id'], unique=False)
          batch_op.create_index(batch_op.f('ix_message_timestamp'), ['timestamp'], unique=False)
  
      with op.batch_alter_table('user', schema=None) as batch_op:
          batch_op.add_column(sa.Column('last_message_read_time', sa.DateTime(), nullable=True))
      # ### end Alembic commands ###
  
  
  def downgrade():
      # ### commands auto generated by Alembic - please adjust! ###
      with op.batch_alter_table('user', schema=None) as batch_op:
          batch_op.drop_column('last_message_read_time')
  
      with op.batch_alter_table('message', schema=None) as batch_op:
          batch_op.drop_index(batch_op.f('ix_message_timestamp'))
          batch_op.drop_index(batch_op.f('ix_message_sender_id'))
          batch_op.drop_index(batch_op.f('ix_message_recipient_id'))
  
      op.drop_table('message')
      # ### end Alembic commands ###
  