sqlalcheym

gistfile1.py

from sqlalchemy import *
from sqlalchemy.orm import *
from sqlalchemy.ext.declarative import declarative_base

Base = declarative_base()


class A(Base):
    __tablename__ = 'a'

    id = Column(Integer, primary_key=True)

    data = Column(String,
                        server_default=FetchedValue())

    __mapper_args__ = {
        "eager_defaults": True  # should not be needed
    }

# should work whether or not this is set
#    __table_args__ = {"implicit_returning": False}


engine = create_engine("postgresql://scott:tiger@localhost/test", echo=True)
Base.metadata.drop_all(engine)
engine.execute("create table a (id serial primary key, data varchar)")
engine.execute("ALTER TABLE a ALTER COLUMN data SET DEFAULT concat(md5(CAST(random() AS TEXT)), '2')")


s = Session(engine)

a1 = A()

s.add(a1)

s.flush()