Class Reference

pydbml/_classes/reference.py:15–120

Class, representing a foreign key constraint. It is a separate object, which is not connected to Table or Column objects and its `sql` property contains the ALTER TABLE clause.

class Reference(SQLObject, DBMLObject):
    '''
    Class, representing a foreign key constraint.
    It is a separate object, which is not connected to Table or Column objects
    and its `sql` property contains the ALTER TABLE clause.
    '''
    required_attributes = ('type', 'col1', 'col2')
    dont_compare_fields = ('database', '_inline')

    def __init__(self,
                 type: Literal['>', '<', '-', '<>'],
                 col1: Union[Column, Collection[Column]],
                 col2: Union[Column, Collection[Column]],
                 name: Optional[str] = None,
                 comment: Optional[str] = None,
                 on_update: Optional[str] = None,
                 on_delete: Optional[str] = None,
                 inline: bool = False):
        self.database = None
        self.type = type
        self.col1 = [col1] if isinstance(col1, Column) else list(col1)
        self.col2 = [col2] if isinstance(col2, Column) else list(col2)
        self.name = name if name else None
        self.comment = comment
        self.on_update = on_update
        self.on_delete = on_delete
        self._inline = inline

    @property
    def inline(self) -> bool:
        return self._inline and not self.type == MANY_TO_MANY

    @inline.setter
    def inline(self, val) -> None:
        self._inline = val

    @property
    def join_table(self) -> Optional[Table]:
        if self.type != MANY_TO_MANY:
            return None

        if self.table1 is None:
            raise TableNotFoundError(f"Cannot generate join table for {self}: table 1 is unknown")
        if self.table2 is None:
            raise TableNotFoundError(f"Cannot generate join table for {self}: table 2 is unknown")

        return Table(
            name=f'{self.table1.name}_{self.table2.name}',
            schema=self.table1.schema,
            columns=(
                Column(name=f'{c.table.name}_{c.name}', type=c.type, not_null=True, pk=True)  # type: ignore
                for c in chain(self.col1, self.col2)
            ),
            abstract=True
        )

    @property
    def table1(self) -> Optional[Table]: