def METHOD_NAME():
    # commands auto generated by Alembic - please adjust! #
    op.execute("DELETE FROM event_copyrights WHERE licence='' or licence IS NULL ",
               execution_options=None)
    op.execute("DELETE FROM sessions WHERE title='' or title IS NULL",
               execution_options=None)
    op.execute("DELETE FROM social_links WHERE link='' or link IS NULL",
               execution_options=None)
    op.execute("DELETE FROM speakers_calls WHERE announcement='' or announcement IS NULL",
               execution_options=None)
    op.execute("DELETE FROM ticket_holders WHERE firstname='' or firstname IS NULL",
               execution_options=None)
    op.execute("DELETE FROM tickets WHERE name='' or name IS NULL",
               execution_options=None)
    op.execute("DELETE FROM tickets WHERE sales_ends_at IS NULL",
               execution_options=None)
    op.execute("DELETE FROM tickets WHERE sales_starts_at IS NULL",
               execution_options=None)
    op.execute("DELETE FROM tickets WHERE type='' or type IS NULL",
               execution_options=None)
    op.execute("DELETE FROM users WHERE _email='' or _email IS NULL",
               execution_options=None)
    op.execute("DELETE FROM users WHERE _password='' or _password IS NULL",
               execution_options=None)
    op.alter_column('event_copyrights', 'licence',
                    existing_type=sa.VARCHAR(),
                    nullable=False)
    op.alter_column('sessions', 'title',
                    existing_type=sa.VARCHAR(),
                    nullable=False)
    op.alter_column('social_links', 'link',
                    existing_type=sa.VARCHAR(),
                    nullable=False)
    op.alter_column('speakers_calls', 'announcement',
                    existing_type=sa.TEXT(),
                    nullable=False)
    op.alter_column('ticket_holders', 'firstname',
                    existing_type=sa.VARCHAR(),
                    nullable=False)
    op.alter_column('tickets', 'name',
                    existing_type=sa.VARCHAR(),
                    nullable=False)
    op.alter_column('tickets', 'sales_ends_at',
                    existing_type=postgresql.TIMESTAMP(timezone=True),
                    nullable=False)
    op.alter_column('tickets', 'sales_starts_at',
                    existing_type=postgresql.TIMESTAMP(timezone=True),
                    nullable=False)
    op.alter_column('tickets', 'type',
                    existing_type=sa.VARCHAR(),
                    nullable=False)
    op.alter_column('users', '_email',
                    existing_type=sa.VARCHAR(length=120),
                    nullable=False)
    op.alter_column('users', '_password',
                    existing_type=sa.VARCHAR(length=128),
                    nullable=False)
    # end Alembic commands #