How to discover table properties from SQLAlchemy mapped object
I have a class mapped with a table, in my case in a declarative way, and I want to "discover" table properties, columns, names, relations, from this class:
engine = create_engine('sqlite:///' + databasePath, echo=True)
# setting up root class for declarative declaration
Base = declarative_base(bind=engine)
class Ship(Base):
__tablename__ = 'ships'
id =开发者_运维知识库 Column(Integer, primary_key=True)
name = Column(String(255))
def __init__(self, name):
self.name = name
def __repr__(self):
return "<Ship('%s')>" % (self.name)
So now my goal is from the "Ship" class to get the table columns and their properties from another piece of code. I guess I can deal with it using instrumentation but is there any way provided by the SQLAlchemy API?
Information you need you can get from Table object:
Ship.__table__.columns
will provide you with columns informationShip.__table__.foreign_keys
will list foreign keysShip.__table__.constraints
,Ship.__table__.indexes
are other properties you might find useful
If declarative base is not used, the answer fails. The following should work no matter how it's initialized
For Class Object:
TableClass.sa_class_manager.mapper.mapped_table.name
For Instance Object:
tableObj.sa_instance_state.mapper.mapped_table.name
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