python - tutorial - sqlalchemy: la inserción masiva del alambique falla: el objeto ''str'' no tiene ningún atributo ''_autoincrement_column''

sqlalchemy tutorial español

Question

Mi modelo se ve como

class Category(UserMixin, db.Model):
    __tablename__ = ''categories''
    uuid = Column(''uuid'', GUID(), default=uuid.uuid4, primary_key=True,
                  unique=True)
    name = Column(''name'', String, nullable=False)
    parent = Column(''parent'', String, nullable=False)
    created_on = Column(''created_on'', sa.types.DateTime(timezone=True),
                        default=datetime.utcnow())
    __table_args__ = (UniqueConstraint(''name'', ''parent''),)

    def __init__(self, name, parent):
        self.name = name
        self.parent = parent

    def __repr__(self):
        return ''<Category:%s:%s:%s>'' % (
            self.uuid, self.name, self.category_type)

donde GUID es sqlalchemy personalizado tipo I crea la tabla usando alembic --autogenerate

 op.create_table(''categories'',
                    sa.Column(''uuid'', UUID(), nullable=False),
                    sa.Column(''name'', sa.String(), nullable=False),
                    sa.Column(''parent'', sa.String(), nullable=False),
                    sa.Column(''created_on'', sa.DateTime(timezone=True),
                              nullable=True),
                    sa.PrimaryKeyConstraint(''uuid''),
                    sa.UniqueConstraint(''name'', ''parent''),
                    sa.UniqueConstraint(''uuid'')
    )

y tabla PostgreSQL como

            Table "public.categories"
   Column   |           Type           | Modifiers
------------+--------------------------+-----------
 uuid       | uuid                     | not null
 name       | character varying        | not null
 parent     | character varying        | not null
 created_on | timestamp with time zone |
Indexes:
    "categories_pkey" PRIMARY KEY, btree (uuid)
    "categories_name_parent_key" UNIQUE CONSTRAINT, btree (name, parent)

Intento ejecutar la revisión y actualizar el db como

def upgrade():
    op.bulk_insert(''categories'',
                   [
                       {''name'': ''first'', ''parent'': ''first_parent''},
                       {''name'': ''second'', ''parent'': ''second_parent''}
                   ]
    )

cuando ejecuto la alembic upgrade head , veo error como

  File "/Users/me/.virtualenvs/envs/project/lib/python2.7/site-packages/alembic/environment.py", line 494, in run_migrations
    self.get_context().run_migrations(**kw)
  File "/Users/me/.virtualenvs/envs/project/lib/python2.7/site-packages/alembic/migration.py", line 211, in run_migrations
    change(**kw)
  File "alembic/versions/491d4f91e0bc_generate_categories_.py", line 21, in upgrade
    {''name'': ''second'', ''parent'': ''second_parent''}
  File "<string>", line 7, in bulk_insert
  File "/Users/me/.virtualenvs/envs/project/lib/python2.7/site-packages/alembic/operations.py", line 710, in bulk_insert
    self.impl.bulk_insert(table, rows)
  File "/Users/me/.virtualenvs/envs/project/lib/python2.7/site-packages/alembic/ddl/impl.py", line 179, in bulk_insert
    table._autoincrement_column = None
AttributeError: ''str'' object has no attribute ''_autoincrement_column''

¿Qué es lo que estoy haciendo mal aquí?

Answer 1

todo lo que tuve que hacer es crear una table antes de bulk_insert, incluso si tengo un esquema explícito en models.py separados

import sqlalchemy as sa
from sqlalchemy.sql import table
from alembic import op

def upgrade():
     categories = table(''categories'',
                       sa.Column(''uuid'', UUID(),
                              primary_key=True,
                              unique=True, autoincrement=False),
                       sa.Column(''name'', String),
                       sa.Column(''parent'', String),
                       sa.Column(''created_on'', sa.types.DateTime(timezone=True),
                              default=datetime.utcnow())
    )
    op.bulk_insert(categories,
                   [
                       {''name'': ''first'', ''parent'': ''first_parent''},
                       {''name'': ''second'', ''parent'': ''second_parent''}
                   ]
    )

y luego pude ejecutar el alembic upgrade head sin problemas y los datos se serializaron con éxito en la base de datos.