You right, I dont have "name" column in "commands" table, thats why If I do
def __init__(self, **kw): kw.setdefault(“name”, “Command”) super(Command, self).__init__(**kw) name = column_property(Column(String(50), default=“Command”), DB_Object.name) I have: "table commands has no column named". I dont need this column in "Command", but in "Command" I need to set "name" of "DB_Object" to value that depends on other "Command" columns. How can I do this? On Friday, May 23, 2014 12:51:14 AM UTC+4, Michael Bayer wrote: > > > On May 22, 2014, at 7:42 AM, Pavel Aborilov <abor...@gmail.com<javascript:>> > wrote: > > Hi! > How can I set default for parent field? > > class DB_Object(Base): > __tablename__ = 'objects' > id = Column(Integer, primary_key=True) > name = Column(String(50), unique=True, nullable=False) > type = Column(String(50)) > __mapper_args__ = { 'polymorphic_identity': 'object', > 'polymorphic_on': type } > > class Command(DB_Object): > __tablename__ = "commands" > id = Column(Integer, ForeignKey('objects.id'), primary_key=True) > name = Column(String(50), default="Command") > > If I try to commit Command object > I have "objects.name may not be NULL” > > > This is all assuming that “name” is the same value on both DB_Object and > on Command. > > Since Command extends from DB_Object, you’d want to remove the “name > “column from the “commands” table - it is redundant vs. the “name” column > that’s on “objects”. > > Alternatively, you can map both “name” columns on Command as follows: > > class Command(DB_Object): > # … > > name = column_property(Column(String(50), default=“Command”), > DB_Object.name) > > However, in either case, you will also need to establish that “default” > value in the constructor (or in the init event, see > http://docs.sqlalchemy.org/en/latest/orm/events.html?highlight=init%20event#sqlalchemy.orm.events.InstanceEvents.init) > > , so that it applies to both “name” columns during flush: > > class Command(DB_Object): > # … > > def __init__(self, **kw): > kw.setdefault(“name”, “Command”) > super(Command, self).__init__(**kw) > > > > > > > > > > -- > You received this message because you are subscribed to the Google Groups > "sqlalchemy" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to sqlalchemy+...@googlegroups.com <javascript:>. > To post to this group, send email to sqlal...@googlegroups.com<javascript:> > . > Visit this group at http://groups.google.com/group/sqlalchemy. > For more options, visit https://groups.google.com/d/optout. > > > -- You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To unsubscribe from this group and stop receiving emails from it, send an email to sqlalchemy+unsubscr...@googlegroups.com. To post to this group, send email to sqlalchemy@googlegroups.com. Visit this group at http://groups.google.com/group/sqlalchemy. For more options, visit https://groups.google.com/d/optout.