[sqlalchemy] Re: Unknown inheritance type question

2008-06-05 Thread Michael Bayer 


this mapping:

transaction_sale_join = join(transactions, sales)
mapper(Sale, transaction_sale_join, inherits=transactions_mapper,
 polymorphic_identity=3, properties={
'line_items': relation(LineItem, backref='sale', cascade='all,
 delete-orphan')
})


is incorrect.  The inherits configuration will create the join from  
transactions-sales for you - Sale should be mapped directly to sales.




On Jun 4, 2008, at 6:29 PM, Brad Wells wrote:


 The complexity of the following setup is that of the transaction type
 Sales also have their own table. I am unsure of how properly establish
 this relationship between Transactions, Sales and TransactionTypes.

 This setup so far allows me to create Sale objects and save them.
 However Sale.query.all() (for example) results in: OperationalError:
 (OperationalError) (1066, Not unique table/alias: 'transactions')

 any advice is appreciated.

 Tables:

 transactions = Table('transactions', meta,
Column('id', Integer, primary_key=True),
Column('transaction_type_id', Integer),
ForeignKeyConstraint(['transaction_type_id'],
 ['transaction_types.id']),
 )

 transaction_types = Table('transaction_types', meta,
Column('id', Integer, primary_key=True),
Column('name', String(15)),
Column('has_line_items', Boolean),
 )

 sales = Table('sales', meta,
Column('id', Integer, primary_key=True),
Column('address', Text),
Column('shipping', Float),
Column('handling', Float),
Column('purchase_order', String(35)),
Column('transaction_id', Integer),
ForeignKeyConstraint(['transaction_id'], ['transactions.id']),
 )

 line_items = Table('line_items', meta,
Column('id', Integer, primary_key=True),
Column('position', Integer),
Column('description', Text),
Column('quantity', Float),
Column('units', String(15)),
Column('unit_rate', Float),
Column('tax', Float),
Column('transaction_id', Integer),
ForeignKeyConstraint(['transaction_id'], ['transactions.id']),
 )

 Classes:

 class Transaction(Entity):
pass

 class TransactionType(Entity):
pass

 class Payment(Transaction):
pass


 class Adjustment(Transaction):
pass


 class Receipt(Transaction):
pass


 # abstract class
 class LineItemTransaction(Transaction):
pass

 class Cost(LineItemTransaction):
pass

 class Sale(LineItemTransaction):
pass

 class LineItem(Entity):
pass

 Mappers:

mapper(TransactionType, transaction_types)

transactions_mapper = mapper(Transaction, transactions,
polymorphic_on=transactions.c.transaction_type_id,
 polymorphic_identity=0,
properties={
'transaction_type': relation(TransactionType,
 backref='transactions'),
})

mapper(Cost, inherits=transactions_mapper, polymorphic_identity=1,
 properties={
'line_items': relation(LineItem, backref='cost', cascade='all,
 delete-orphan')
})
mapper(Payment, inherits=transactions_mapper,
 polymorphic_identity=2)

mapper(Receipt, inherits=transactions_mapper,
 polymorphic_identity=4)

mapper(Adjustment, inherits=transactions_mapper,
 polymorphic_identity=5)

transaction_sale_join = join(transactions, sales)
mapper(Sale, transaction_sale_join, inherits=transactions_mapper,
 polymorphic_identity=3, properties={
'line_items': relation(LineItem, backref='sale', cascade='all,
 delete-orphan')
})

mapper(LineItem, line_items)

 -brad

 


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[sqlalchemy] Re: Unknown inheritance type question

2008-06-05 Thread Brad Wells 

Thank you very much. again.

-brad

On Jun 5, 10:57 am, Michael Bayer [EMAIL PROTECTED] wrote:
 this mapping:

 transaction_sale_join = join(transactions, sales)
 mapper(Sale, transaction_sale_join, inherits=transactions_mapper,
  polymorphic_identity=3, properties={
 'line_items': relation(LineItem, backref='sale', cascade='all,
  delete-orphan')
 })

 is incorrect.  The inherits configuration will create the join from
 transactions-sales for you - Sale should be mapped directly to sales.

 On Jun 4, 2008, at 6:29 PM, Brad Wells wrote:



  The complexity of the following setup is that of the transaction type
  Sales also have their own table. I am unsure of how properly establish
  this relationship between Transactions, Sales and TransactionTypes.

  This setup so far allows me to create Sale objects and save them.
  However Sale.query.all() (for example) results in: OperationalError:
  (OperationalError) (1066, Not unique table/alias: 'transactions')

  any advice is appreciated.

  Tables:

  transactions = Table('transactions', meta,
 Column('id', Integer, primary_key=True),
 Column('transaction_type_id', Integer),
 ForeignKeyConstraint(['transaction_type_id'],
  ['transaction_types.id']),
  )

  transaction_types = Table('transaction_types', meta,
 Column('id', Integer, primary_key=True),
 Column('name', String(15)),
 Column('has_line_items', Boolean),
  )

  sales = Table('sales', meta,
 Column('id', Integer, primary_key=True),
 Column('address', Text),
 Column('shipping', Float),
 Column('handling', Float),
 Column('purchase_order', String(35)),
 Column('transaction_id', Integer),
 ForeignKeyConstraint(['transaction_id'], ['transactions.id']),
  )

  line_items = Table('line_items', meta,
 Column('id', Integer, primary_key=True),
 Column('position', Integer),
 Column('description', Text),
 Column('quantity', Float),
 Column('units', String(15)),
 Column('unit_rate', Float),
 Column('tax', Float),
 Column('transaction_id', Integer),
 ForeignKeyConstraint(['transaction_id'], ['transactions.id']),
  )

  Classes:

  class Transaction(Entity):
 pass

  class TransactionType(Entity):
 pass

  class Payment(Transaction):
 pass

  class Adjustment(Transaction):
 pass

  class Receipt(Transaction):
 pass

  # abstract class
  class LineItemTransaction(Transaction):
 pass

  class Cost(LineItemTransaction):
 pass

  class Sale(LineItemTransaction):
 pass

  class LineItem(Entity):
 pass

  Mappers:

 mapper(TransactionType, transaction_types)

 transactions_mapper = mapper(Transaction, transactions,
 polymorphic_on=transactions.c.transaction_type_id,
  polymorphic_identity=0,
 properties={
 'transaction_type': relation(TransactionType,
  backref='transactions'),
 })

 mapper(Cost, inherits=transactions_mapper, polymorphic_identity=1,
  properties={
 'line_items': relation(LineItem, backref='cost', cascade='all,
  delete-orphan')
 })
 mapper(Payment, inherits=transactions_mapper,
  polymorphic_identity=2)

 mapper(Receipt, inherits=transactions_mapper,
  polymorphic_identity=4)

 mapper(Adjustment, inherits=transactions_mapper,
  polymorphic_identity=5)

 transaction_sale_join = join(transactions, sales)
 mapper(Sale, transaction_sale_join, inherits=transactions_mapper,
  polymorphic_identity=3, properties={
 'line_items': relation(LineItem, backref='sale', cascade='all,
  delete-orphan')
 })

 mapper(LineItem, line_items)

  -brad
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