45 lines
1.2 KiB
Python
45 lines
1.2 KiB
Python
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from sqlalchemy.orm import DeclarativeBase, declared_attr, Mapped, mapped_column, relationship, add_mapped_attribute
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def to_snake_case(name: str) -> str:
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return "".join(["_" + i.lower() if i.isupper() else i for i in name]).lstrip("_")
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def bidirectional_relationship(cls, foreign_table_cls):
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"""Create a bidirectional relationship between two table-classes."""
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column_name = f"{to_snake_case(cls.__name__)}"
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column_name = f"{column_name}es" if column_name.endswith("s") else f"{column_name}s"
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add_mapped_attribute(
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foreign_table_cls,
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column_name,
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relationship(cls,
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back_populates=foreign_table_cls.__tablename__,
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cascade="all, delete-orphan",
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collection_class=set,
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)
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)
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return relationship(foreign_table_cls.__name__, back_populates=column_name)
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class Base(DeclarativeBase):
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__abstract__ = True
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id: Mapped[int] = mapped_column(primary_key=True, sort_order=-1000000)
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# noinspection PyMethodParameters
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@declared_attr.directive
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def __tablename__(cls) -> str:
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"""Default table name in Database is derived from Class Name"""
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return to_snake_case(cls.__name__)
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# noinspection PyPep8Naming
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