Problem with sqlAlchemy model?

SQLAlchemy is not my strongest skill, but I think this property is wrong: properties = {'children' : relationship('DataType', backref=backref(obj, cascade="all,delete"))} I think this should be: properties = {'children' : relationship(DataType, backref=backref(obj, cascade="all,delete"))} I.E. , the reference to the DataType is the class, not a string.

I was about to say this was probably not the problem, but I think you may be right: the declarative extension does allow you to refer to as-yet-undefined classes with strings, but only within the class declaration I think. – Steven May 11 at 18:26 Yes, thanks that was the main problem. Also I needed to pass str(obj) to backref.

– Bogdan May 12 at 7:13.

I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.