SqlAlchemy select 语句 where 子句被忽略

Question

• Python 3.9
• SqlAlchemy v2.0.0
• SQLite

我的 SqlAlchemy 模型：

Base: DeclarativeMeta = declarative_base()

class TableAModel(Base):
    __tablename__ = "TableA"

    id: Mapped[uuid.UUID] = mapped_column(primary_key=True)
    last_updated: Mapped[str] = mapped_column(nullable=True)

    def __repr__(self):
        """Return a string representation of the object."""
        return (
            f"<TableA(id='{str(self.id)}', "
            f"last_updated='{self.last_updated}')>"
        )

选择语句：

select_statement = select(TableAModel).where(
    TableAModel.id == some_existing_guid
)
results = self.sql_client.execute_select_statement(
    select_statement, select_first=True
)

db_layer.py：

def execute(self, statement: Select, select_first: bool = False):
    """Execute SELECT statement."""
    with self.__get_session__() as session:
        session.begin()
        try:
            result = session.execute(statement)
            if select_first:
                return result.first()
            return result.fetchall()
        except SQLAlchemyError as err:
            get_logger_adapter().error(
                "Error occurred during select:", exc_info=True
            )
            raise err

这遵循 SqlAlchemy 文档中有关如何通过 id 执行简单查询的指南。我的 where 子句没有任何作用并且总是返回 None 。我已验证该行是否存在且具有正确的 id。不带 where 子句的常规选择确实会返回现有行。我将原始查询转储到控制台，查询看起来是正确的。

SELECT "TableA".id, "TableA".last_updated 
FROM "TableA" 
WHERE "TableA".id = :id_1

Answer 1

必须更换我的主键数据类型。我注意到在 SQLite 中，我的 uuid 映射到

varchar

。一旦我将映射交换为字符串，我的 where 子句就开始工作。

id: Mapped[str] = mapped_column(primary_key=True)