Python sqlalchemy.dialects.postgresql 模块，DOUBLE_PRECISION 实例源码

def downgrade():
    # ### commands auto generated by Alembic - please adjust! ###
    op.add_column('label_event', sa.Column('label', sa.VARCHAR(length=255), autoincrement=False, nullable=True))
    op.add_column('dataset', sa.Column('probability', postgresql.DOUBLE_PRECISION(precision=53), autoincrement=False, nullable=True))
    op.add_column('problem', sa.Column('label', sa.Unicode(length=255), nullable=True))

    op.execute('''
        UPDATE label_event SET label = (SELECT label FROM problem_label WHERE problem_label.id = label_event.label_id)
    ''')
    op.execute('''
        UPDATE dataset SET probability = (SELECT probability FROM dataset_label_probability WHERE dataset_label_probability.data_id = dataset.id)
    ''')
    op.execute('''
        UPDATE problem SET label = (SELECT label FROM problem_label WHERE problem_label.problem_id = problem.id)
    ''')

    op.alter_column('label_event', 'label', nullable=False)
    op.alter_column('problem', 'label', nullable=False)

    op.drop_column('problem', 'name')
    op.drop_index(op.f('ix_label_event_label_id'), table_name='label_event')
    op.drop_column('label_event', 'label_id')
    op.drop_index(op.f('ix_dataset_label_probability_label_id'), table_name='dataset_label_probability')
    op.drop_index(op.f('ix_dataset_label_probability_data_id'), table_name='dataset_label_probability')
    op.drop_table('dataset_label_probability')
    op.drop_table('problem_label')
    # ### end Alembic commands ###

def upgrade():
    # ### commands auto generated by Alembic - please adjust! ###
    op.alter_column('items', 'price',
               existing_type=postgresql.DOUBLE_PRECISION(precision=53),
               nullable=True)
    # ### end Alembic commands ###

def downgrade():
    # ### commands auto generated by Alembic - please adjust! ###
    op.alter_column('items', 'price',
               existing_type=postgresql.DOUBLE_PRECISION(precision=53),
               nullable=False)
    # ### end Alembic commands ###

def downgrade():
    """Downgrade the database to an older revision."""
    # ### commands auto generated by Alembic - please adjust! ###
    op.create_table('stacks',
                    sa.Column('id', sa.INTEGER(),
                              server_default=sa.text("nextval('stacks_id_seq'::regclass)"),
                              nullable=False),
                    sa.Column('is_ref_stack', sa.BOOLEAN(), autoincrement=False, nullable=False),
                    sa.Column('stack_json', postgresql.JSONB(astext_type=sa.Text()),
                              autoincrement=False, nullable=False),
                    sa.PrimaryKeyConstraint('id', name='stacks_pkey'),
                    postgresql_ignore_search_path=False)
    op.create_table('similar_components',
                    sa.Column('id', sa.INTEGER(), nullable=False),
                    sa.Column('fromcomponent', sa.TEXT(), autoincrement=False, nullable=False),
                    sa.Column('tocomponent', sa.TEXT(), autoincrement=False, nullable=False),
                    sa.Column('similarity_distance', postgresql.DOUBLE_PRECISION(precision=53),
                              autoincrement=False, nullable=False),
                    sa.PrimaryKeyConstraint('id', name='similar_components_pkey'),
                    sa.UniqueConstraint('fromcomponent', 'tocomponent', name='sim_comps'))
    op.create_table('similar_stacks',
                    sa.Column('id', sa.INTEGER(), nullable=False),
                    sa.Column('analysis', postgresql.JSONB(astext_type=sa.Text()),
                              autoincrement=False, nullable=True),
                    sa.Column('similar_stack_id', sa.INTEGER(), autoincrement=False,
                              nullable=False),
                    sa.Column('similarity_value', postgresql.DOUBLE_PRECISION(precision=53),
                              autoincrement=False, nullable=False),
                    sa.Column('stack_id', sa.INTEGER(), autoincrement=False, nullable=False),
                    sa.ForeignKeyConstraint(['similar_stack_id'], ['stacks.id'],
                                            name='similar_stacks_similar_stack_id_fkey'),
                    sa.ForeignKeyConstraint(['stack_id'], ['stacks.id'],
                                            name='similar_stacks_stack_id_fkey'),
                    sa.PrimaryKeyConstraint('id', name='similar_stacks_pkey'),
                    sa.UniqueConstraint('stack_id', 'similar_stack_id', name='sim_unique'))
    op.create_table('esmarker',
                    sa.Column('id', sa.INTEGER(), nullable=False),
                    sa.Column('worker_result_id', sa.INTEGER(), autoincrement=False,
                              nullable=True),
                    sa.ForeignKeyConstraint(['worker_result_id'], ['worker_results.id'],
                                            name='esmarker_worker_result_id_fkey'),
                    sa.PrimaryKeyConstraint('id', name='esmarker_pkey'))
    # ### end Alembic commands ###