Postgres SQLAlchemy: Additional arguments should be named <dialectname>

I am using postgres database and sqlalchemy in my python code, I created schemas and models and I want to use ForeignKey, but I got this error message:

Additional arguments should be named <dialectname>_<argument>, got 'ForeignKey'

my code:

class table1(Base):
    __tablename__ = 'table1'
    first_id = Column(
        Integer, unique=True, nullable=False, primary_key=True, autoincrement=True
    )


class table2(Base):
    __tablename__ = 'table2'
    second_id = Column(
        Integer,
        nullable=False,
        primary_key=True,
    )
    second = Column(Integer, nullable=False, primary_key=True, ForeignKey=('table1.first_id'))

Could anyone help me with this? Thanks.

CodePudding user response：

You need to import ForeignKey from sqlalchemy and create it as positional argument to Column.

from sqlalchemy import ForeignKey

class table1(Base):
    __tablename__ = 'table1'
    first_id = Column(
        Integer, unique=True, nullable=False, primary_key=True, autoincrement=True
    )


class table2(Base):
    __tablename__ = 'table2'
    second_id = Column(
        Integer,
        nullable=False,
        primary_key=True,
    )
    second = Column(Integer, ForeignKey('table1.first_id'), nullable=False, primary_key=True)

Documentation

ForeignKey

Column params