bug: Implicit autoincrement with SQLAlchemy integer PK

[brian-pond]

Situation

Consider the following excerpt from SQLAlchemy documentation about the autoincrement attribute:

The default value is the string "auto", which indicates that a single-column (i.e. non-composite) primary key that is of an INTEGER type with no other client-side or server-side default constructs indicated should receive auto increment semantics automatically. Other values include True (force this column to have auto-increment semantics for a composite primary key as well), False (this column should never have auto-increment semantics), and the string "ignore_fk" (special-case for foreign key columns, see below).

...

DDL rendering (i.e. MetaData.create_all(), Table.create()): When used on a Column that has no other default-generating construct associated with it (such as a Sequence or Identity construct), the parameter will imply that database-specific keywords such as PostgreSQL SERIAL, MySQL AUTO_INCREMENT, or IDENTITY on SQL Server should also be rendered. Not every database backend has an “implied” default generator available; for example the Oracle Database backends always needs an explicit construct such as Identity to be included with a Column in order for the DDL rendered to include auto-generating constructs to also be produced in the database.

Problem

Assume a model has a single-column (i.e. non-composite) primary key that is of an INTEGER type. And no other special attributes.

dbconform currently doesn't understand this implies writing DDL to create an auto-generated Identity column.

(shame on SQLAlchemy for not following the Zen: explicit is better than implicit

[brian-pond]

Fixed with this commit: e458068

[brian-pond]

While working on another app, this model is not creating an Identity column. My guess is my previous fix only worked for SQLAlchemy, and not SQLModel.

class ProductSupplier(SQLModel, table=True):
    __tablename__ = "product_supplier"
    id: int | None = Field(default=None, primary_key=True)
    product_id: str = Field(foreign_key="product.product_id", min_length=1, index=True)
    supplier_id: str = Field(min_length=1, description="Supplier identifier.", index=True)
    lead_time_days: int = Field(ge=0, description="Lead time in days.")
    effective_from: date | None = Field(
        default=None,
        description="Effective from date; null means beginning of time.",
    )
    effective_to: date | None = Field(
        default=None,
        description="Effective to date; null means end of time.",
    )