Select statement with more than 4 models causes a type error

[dtip]

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Example Code

from sqlmodel import Field, Session, SQLModel, col, create_engine, select


# Define your models
class Author(SQLModel, table=True):
    id: int | None = Field(default=None, primary_key=True)
    name: str


class Publisher(SQLModel, table=True):
    id: int | None = Field(default=None, primary_key=True)
    name: str


class Genre(SQLModel, table=True):
    id: int | None = Field(default=None, primary_key=True)
    name: str


class Series(SQLModel, table=True):
    id: int | None = Field(default=None, primary_key=True)
    name: str


class Book(SQLModel, table=True):
    id: int | None = Field(default=None, primary_key=True)
    title: str
    author_id: int = Field(foreign_key="author.id")
    publisher_id: int = Field(foreign_key="publisher.id")
    genre_id: int = Field(foreign_key="genre.id")
    series_id: int = Field(foreign_key="series.id")


# Create engine and tables
engine = create_engine("sqlite:///database.db")
SQLModel.metadata.create_all(engine)

with Session(engine) as session:
    # Select statement with more than 4 models triggers a type error
    statement = (
        select(Book, Author, Publisher, Genre, Series)  # Error: No overloads for "select" match the provided arguments
        .join(Author, col(Book.author_id) == col(Author.id))
        .join(Publisher, col(Book.publisher_id) == col(Publisher.id))
        .join(Genre, col(Book.genre_id) == col(Genre.id))
        .join(Series, col(Book.series_id) == col(Series.id))
    )

    results = session.exec(statement).all()

    for book, author, publisher, genre, series in results:
        print(f"{book.title} by {author.name}")
        print(f"Published by {publisher.name} - Genre: {genre.name} - Series: {series.name}")

Description

Writing a select statement with more than 4 models triggers the type error Error: No overloads for "select" match the provided arguments

Operating System

Linux

Operating System Details

No response

SQLModel Version

0.0.27

Python Version

3.14.0

Additional Context

No response

[YuriiMotov]

Thanks for reporting!

We already have an issue to track it: #271

And there is a PR: #1333