Metadata.create_all call with list of tables as argument fails with "TypeError: object of type 'InstrumentedAttribute' has no len()"

[gmichaeljaison]

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Example Code

import sqlalchemy
import sqlmodel


class Session(sqlmodel.SQLModel, table=True):
    uid: str = sqlmodel.Field(primary_key=True)
    name: str


engine = sqlmodel.create_engine("sqlite:///dummy.db", echo=True)
sqlmodel.SQLModel.metadata.create_all(engine, [Session])

Description

metadata.create_all method is supposed to accept list of tables as second argument and only create those tables in the dataset instead of all. But it throws an error.

Operating System

macOS

Operating System Details

No response

SQLModel Version

0.0.16

Python Version

Python 3.12.2

Additional Context

---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
Cell In[2], [line 2](vscode-notebook-cell:?execution_count=2&line=2)
      [1](vscode-notebook-cell:?execution_count=2&line=1) engine = sqlmodel.create_engine("sqlite:///dummy2.db", echo=True)
----> [2](vscode-notebook-cell:?execution_count=2&line=2) sqlmodel.SQLModel.metadata.create_all(engine, [Session])

File [~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/sql/schema.py:5825](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/sql/schema.py:5825), in MetaData.create_all(self, bind, tables, checkfirst)
   [5801](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/sql/schema.py:5801) def create_all(
   [5802](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/sql/schema.py:5802)     self,
   [5803](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/sql/schema.py:5803)     bind: _CreateDropBind,
   [5804](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/sql/schema.py:5804)     tables: Optional[_typing_Sequence[Table]] = None,
   [5805](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/sql/schema.py:5805)     checkfirst: bool = True,
   [5806](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/sql/schema.py:5806) ) -> None:
   [5807](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/sql/schema.py:5807)     """Create all tables stored in this metadata.
   [5808](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/sql/schema.py:5808) 
   [5809](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/sql/schema.py:5809)     Conditional by default, will not attempt to recreate tables already
   (...)
   [5823](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/sql/schema.py:5823) 
   [5824](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/sql/schema.py:5824)     """
-> [5825](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/sql/schema.py:5825)     bind._run_ddl_visitor(
   [5826](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/sql/schema.py:5826)         ddl.SchemaGenerator, self, checkfirst=checkfirst, tables=tables
   [5827](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/sql/schema.py:5827)     )

File [~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/engine/base.py:3255](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/engine/base.py:3255), in Engine._run_ddl_visitor(self, visitorcallable, element, **kwargs)
   [3248](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/engine/base.py:3248) def _run_ddl_visitor(
   [3249](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/engine/base.py:3249)     self,
   [3250](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/engine/base.py:3250)     visitorcallable: Type[Union[SchemaGenerator, SchemaDropper]],
   [3251](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/engine/base.py:3251)     element: SchemaItem,
   [3252](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/engine/base.py:3252)     **kwargs: Any,
   [3253](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/engine/base.py:3253) ) -> None:
   [3254](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/engine/base.py:3254)     with self.begin() as conn:
-> [3255](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/engine/base.py:3255)         conn._run_ddl_visitor(visitorcallable, element, **kwargs)

File [~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/engine/base.py:2461](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/engine/base.py:2461), in Connection._run_ddl_visitor(self, visitorcallable, element, **kwargs)
   [2449](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/engine/base.py:2449) def _run_ddl_visitor(
   [2450](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/engine/base.py:2450)     self,
   [2451](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/engine/base.py:2451)     visitorcallable: Type[Union[SchemaGenerator, SchemaDropper]],
   [2452](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/engine/base.py:2452)     element: SchemaItem,
   [2453](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/engine/base.py:2453)     **kwargs: Any,
   [2454](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/engine/base.py:2454) ) -> None:
   [2455](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/engine/base.py:2455)     """run a DDL visitor.
   [2456](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/engine/base.py:2456) 
   [2457](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/engine/base.py:2457)     This method is only here so that the MockConnection can change the
   [2458](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/engine/base.py:2458)     options given to the visitor so that "checkfirst" is skipped.
   [2459](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/engine/base.py:2459) 
   [2460](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/engine/base.py:2460)     """
-> [2461](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/engine/base.py:2461)     visitorcallable(self.dialect, self, **kwargs).traverse_single(element)

File [~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/sql/visitors.py:664](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/sql/visitors.py:664), in ExternalTraversal.traverse_single(self, obj, **kw)
    [662](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/sql/visitors.py:662) meth = getattr(v, "visit_%s" % obj.__visit_name__, None)
    [663](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/sql/visitors.py:663) if meth:
--> [664](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/sql/visitors.py:664)     return meth(obj, **kw)

File [~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/sql/ddl.py:897](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/sql/ddl.py:897), in SchemaGenerator.visit_metadata(self, metadata)
    [893](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/sql/ddl.py:893) else:
    [894](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/sql/ddl.py:894)     tables = list(metadata.tables.values())
    [896](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/sql/ddl.py:896) collection = sort_tables_and_constraints(
--> [897](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/sql/ddl.py:897)     [t for t in tables if self._can_create_table(t)]
    [898](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/sql/ddl.py:898) )
    [900](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/sql/ddl.py:900) seq_coll = [
    [901](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/sql/ddl.py:901)     s
    [902](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/sql/ddl.py:902)     for s in metadata._sequences.values()
    [903](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/sql/ddl.py:903)     if s.column is None and self._can_create_sequence(s)
    [904](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/sql/ddl.py:904) ]
    [906](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/sql/ddl.py:906) event_collection = [t for (t, fks) in collection if t is not None]

File [~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/sql/ddl.py:858](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/sql/ddl.py:858), in SchemaGenerator._can_create_table(self, table)
    [857](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/sql/ddl.py:857) def _can_create_table(self, table):
--> [858](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/sql/ddl.py:858)     self.dialect.validate_identifier(table.name)
    [859](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/sql/ddl.py:859)     effective_schema = self.connection.schema_for_object(table)
    [860](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/sql/ddl.py:860)     if effective_schema:

File [~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/engine/default.py:609](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/engine/default.py:609), in DefaultDialect.validate_identifier(self, ident)
    [608](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/engine/default.py:608) def validate_identifier(self, ident):
--> [609](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/engine/default.py:609)     if len(ident) > self.max_identifier_length:
    [610](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/engine/default.py:610)         raise exc.IdentifierError(
    [611](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/engine/default.py:611)             "Identifier '%s' exceeds maximum length of %d characters"
    [612](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/engine/default.py:612)             % (ident, self.max_identifier_length)
    [613](/~/.pyenv/versions/3.12.2/envs/vivid-notebook/lib/python3.12/site-packages/sqlalchemy/engine/default.py:613)         )

TypeError: object of type 'InstrumentedAttribute' has no len()

[joachimhuet]

Yes, if you dive in the code you see that tables takes the table from metadata.
So you will have to use it like so in order to take the Table object and not the SQLModel:

...
SQLModel.metadata.create_all(engine, tables=[SQLModel.metadata.tables["session"]])