[英]SQLAlchemy: Possible to declare a column as primary key declaratively?
I have a base class mixin: 我有一个基类mixin:
class MyColumns(object):
id = Column(Integer)
foo = Column(Integer)
bar = Column(Integer)
class MyMainTable(MyColumns, Base):
__tablename__ = 'main_table'
pk_id = PrimaryKeyConstraint("id")
I want to be able to declare id
as the PK on MyMainTable. 我希望能够将
id
声明为MyMainTable上的PK。 I can't declare it as PK within MyColumns
, because I need to use MyColumns
in another table, where id is NOT the PK (done for auditing purposes). 我无法在
MyColumns
其声明为PK,因为我需要在另一个表中使用MyColumns
,其中id不是PK(出于审计目的而做)。 When I run the above code, I get 当我运行上面的代码时,我得到
sqlalchemy.exc.ArgumentError: Mapper Mapper|MyMainTable|main_table could not assemble any primary key columns for mapped table 'main_table'
Is there any way to add the PK declaration this way? 有什么办法可以这样添加PK声明吗?
I found the solution as documented here: http://docs.sqlalchemy.org/en/rel_0_9/core/constraints.html#setting-up-constraints-when-using-the-declarative-orm-extension 我找到了此处记录的解决方案: http : //docs.sqlalchemy.org/en/rel_0_9/core/constraints.html#setting-up-constraints-when-using-the-declarative-orm-extension
You need to add the constraints to __table_args__
: 您需要将约束添加到
__table_args__
:
class MyColumns(object):
id = Column(Integer)
foo = Column(Integer)
bar = Column(Integer)
class MyMainTable(MyColumns, Base):
__tablename__ = 'main_table'
__table_args__ = (
PrimaryKeyConstraint("id", name="pk_id"),
)
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