Re: [sqlalchemy] Discriminator on association

[Edu Ferreira]

It works. Thanks.

Em segunda-feira, 5 de fevereiro de 2018 14:29:29 UTC-2, Mike Bayer 
escreveu:
>
> On Mon, Feb 5, 2018 at 8:40 AM, Edu Ferreira  > wrote: 
> > Hello, i implemented a generic foreign key/relationship, using this 
> example: 
> > 
> http://docs.sqlalchemy.org/en/latest/_modules/examples/generic_associations/discriminator_on_association.html
>  
> > 
> > In the example addresses is passing in constructor: 
> > 
> > session.add_all([ 
> > Customer( 
> > name='customer 1', 
> > addresses=[ 
> > Address( 
> > street='123 anywhere street', 
> > city="New York", 
> > zip="10110"), 
> > Address( 
> > street='40 main street', 
> > city="San Francisco", 
> > zip="95732") 
> > ] 
> > ), 
> > Supplier( 
> > company_name="Ace Hammers", 
> > addresses=[ 
> > Address( 
> > street='2569 west elm', 
> > city="Detroit", 
> > zip="56785") 
> > ] 
> > ), 
> > ]) 
> > 
> > 
> > 
> > But if i try to do something like this: 
> > 
> > _cust = Customer('name') 
> > session.add(_cust) 
> > session.commit() 
> > 
> > #And After try to use "addresses" 
> > 
> > _cust.addresses.append(Address(street='2569 west elm',city="Detroit", 
> > zip="56785")) 
> > #It doens't work, "addresses" is None. 
> > 
> > 
> > Is there any way to use this without pass "addresses" in the 
> constructor? 
> > I'm using mysql and sqlachemy version is '1.1.15'. 
>
> the proxy is being used slightly oddly here, in that 
> Customer.address_association is a scalar but then 
> Customer.address_association.addresses is a list.  The proxy isn't 
> smart enough to figure out that it needs to initialize a new 
> CustomerAddressAssociation when you say something like 
> customer.addresses.append.  So you need to set one up by assigning 
> first:  customer.addresses = [], now there is a 
> customer.address_association set up and append() will work .You 
> can do this assignment in the constructor of Customer if you want. 
>
> I never use this style, I always use table_per_related or 
> table_per_association. 
>
>
>
>
>
> > 
> > -- 
> > SQLAlchemy - 
> > The Python SQL Toolkit and Object Relational Mapper 
> > 
> > http://www.sqlalchemy.org/ 
> > 
> > To post example code, please provide an MCVE: Minimal, Complete, and 
> > Verifiable Example. See http://stackoverflow.com/help/mcve for a full 
> > description. 
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>

-- 
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http://www.sqlalchemy.org/

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Re: [sqlalchemy] Discriminator on association

[Mike Bayer]

On Mon, Feb 5, 2018 at 8:40 AM, Edu Ferreira  wrote:
> Hello, i implemented a generic foreign key/relationship, using this example:
> http://docs.sqlalchemy.org/en/latest/_modules/examples/generic_associations/discriminator_on_association.html
>
> In the example addresses is passing in constructor:
>
> session.add_all([
> Customer(
> name='customer 1',
> addresses=[
> Address(
> street='123 anywhere street',
> city="New York",
> zip="10110"),
> Address(
> street='40 main street',
> city="San Francisco",
> zip="95732")
> ]
> ),
> Supplier(
> company_name="Ace Hammers",
> addresses=[
> Address(
> street='2569 west elm',
> city="Detroit",
> zip="56785")
> ]
> ),
> ])
>
>
>
> But if i try to do something like this:
>
> _cust = Customer('name')
> session.add(_cust)
> session.commit()
>
> #And After try to use "addresses"
>
> _cust.addresses.append(Address(street='2569 west elm',city="Detroit",
> zip="56785"))
> #It doens't work, "addresses" is None.
>
>
> Is there any way to use this without pass "addresses" in the constructor?
> I'm using mysql and sqlachemy version is '1.1.15'.

the proxy is being used slightly oddly here, in that
Customer.address_association is a scalar but then
Customer.address_association.addresses is a list.  The proxy isn't
smart enough to figure out that it needs to initialize a new
CustomerAddressAssociation when you say something like
customer.addresses.append.  So you need to set one up by assigning
first:  customer.addresses = [], now there is a
customer.address_association set up and append() will work .You
can do this assignment in the constructor of Customer if you want.

I never use this style, I always use table_per_related or table_per_association.





>
> --
> SQLAlchemy -
> The Python SQL Toolkit and Object Relational Mapper
>
> http://www.sqlalchemy.org/
>
> To post example code, please provide an MCVE: Minimal, Complete, and
> Verifiable Example. See http://stackoverflow.com/help/mcve for a full
> description.
> ---
> 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.
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> For more options, visit https://groups.google.com/d/optout.

-- 
SQLAlchemy - 
The Python SQL Toolkit and Object Relational Mapper

http://www.sqlalchemy.org/

To post example code, please provide an MCVE: Minimal, Complete, and Verifiable 
Example.  See  http://stackoverflow.com/help/mcve for a full description.
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[sqlalchemy] Discriminator on association

[Edu Ferreira]

Hello, i implemented a generic foreign key/relationship, using this example:
http://docs.sqlalchemy.org/en/latest/_modules/examples/generic_associations/discriminator_on_association.html

In the example addresses is passing in constructor:

session.add_all([
Customer(
name='customer 1',
addresses=[
Address(
street='123 anywhere street',
city="New York",
zip="10110"),
Address(
street='40 main street',
city="San Francisco",
zip="95732")
]
),
Supplier(
company_name="Ace Hammers",
addresses=[
Address(
street='2569 west elm',
city="Detroit",
zip="56785")
]
),
])



But if i try to do something like this:

_cust = Customer('name')
session.add(_cust)
session.commit()

#And After try to use "addresses"

_cust.addresses.append(Address(street='2569 west elm',city="Detroit", 
zip="56785"))
#It doens't work, "addresses" is None.


Is there any way to use this without pass "addresses" in the constructor? 
I'm using mysql and sqlachemy version is '1.1.15'.

-- 
SQLAlchemy - 
The Python SQL Toolkit and Object Relational Mapper

http://www.sqlalchemy.org/

To post example code, please provide an MCVE: Minimal, Complete, and Verifiable 
Example.  See  http://stackoverflow.com/help/mcve for a full description.
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