Re: [sqlalchemy] ForeignKeyConstraint using Forward Declared Model
On Tue, Sep 4, 2018 at 11:00 PM, Alex Rothberg wrote:
> I tracked down the error on my side. Looks like I have to use the table name
> rather than the model name (doh) in the string. That being said, there may
> still be a bug in sqla where it tries to read the name off a join (rather
> than a table).
>
> That being said, any reason not to support the lambda syntax for
> ForeignKeyConstraint rather than just the string syntax?
the lambda thing currently is specific to Declarative and the ORM. I
guess FKC could do sometihng similar as well but i would need a
contributor to work on writing some tests and the implementation for
this.lambdas for declarative are useful because we sometimes
prefer that when writing out a big primaryjoin for relationship() or
something like that. the remote columns for an FKC OTOH are just
those names. Although, it does make it possible to have FKCs across
two MetaData objects that were declared at different times...that
actually is useful.I'm interested in alternatives to the whole
MetaData thing someday and perhaps using lambdas instead of strings
could be part of it.
>
>
> On Tuesday, September 4, 2018 at 10:43:13 PM UTC-4, Alex Rothberg wrote:
>>
>> You're right the error I posted is coming from somewhere else. I am trying
>> to get a stripped down example. In the meantime, it looks like when I add
>> the additional fk constraint, model.__mapper__.get_property(property_name)
>> on a different model starts failing.
>>
>> File
>> "/Users/alex/.pyenv/versions/api2/lib/python3.7/site-packages/marshmallow_sqlalchemy/convert.py",
>> line 151, in field_for
>> prop = model.__mapper__.get_property(property_name)
>> File
>> "/Users/alex/.pyenv/versions/api2/lib/python3.7/site-packages/sqlalchemy/orm/mapper.py",
>> line 1923, in get_property
>> configure_mappers()
>> File
>> "/Users/alex/.pyenv/versions/api2/lib/python3.7/site-packages/sqlalchemy/orm/mapper.py",
>> line 3033, in configure_mappers
>> mapper._post_configure_properties()
>> File
>> "/Users/alex/.pyenv/versions/api2/lib/python3.7/site-packages/sqlalchemy/orm/mapper.py",
>> line 1832, in _post_configure_properties
>> prop.init()
>> File
>> "/Users/alex/.pyenv/versions/api2/lib/python3.7/site-packages/sqlalchemy/orm/interfaces.py",
>> line 183, in init
>> self.do_init()
>> File
>> "/Users/alex/.pyenv/versions/api2/lib/python3.7/site-packages/sqlalchemy/orm/relationships.py",
>> line 1656, in do_init
>> self._setup_join_conditions()
>> File
>> "/Users/alex/.pyenv/versions/api2/lib/python3.7/site-packages/sqlalchemy/orm/relationships.py",
>> line 1731, in _setup_join_conditions
>> can_be_synced_fn=self._columns_are_mapped
>> File
>> "/Users/alex/.pyenv/versions/api2/lib/python3.7/site-packages/sqlalchemy/orm/relationships.py",
>> line 1998, in __init__
>> self._determine_joins()
>> File
>> "/Users/alex/.pyenv/versions/api2/lib/python3.7/site-packages/sqlalchemy/orm/relationships.py",
>> line 2082, in _determine_joins
>> consider_as_foreign_keys=consider_as_foreign_keys
>> File "", line 2, in join_condition
>> File
>> "/Users/alex/.pyenv/versions/api2/lib/python3.7/site-packages/sqlalchemy/sql/selectable.py",
>> line 964, in _join_condition
>> a, a_subset, b, consider_as_foreign_keys)
>> File
>> "/Users/alex/.pyenv/versions/api2/lib/python3.7/site-packages/sqlalchemy/sql/selectable.py",
>> line 1021, in _joincond_scan_left_right
>> if nrte.table_name == b.name:
>> AttributeError: 'Join' object has no attribute 'name'
>>
>>
>> On Tuesday, September 4, 2018 at 9:40:11 PM UTC-4, Mike Bayer wrote:
>>>
>>> On Tue, Sep 4, 2018 at 7:54 PM, Alex Rothberg wrote:
>>> > Is it possible to set up a `ForeignKeyConstraint` that uses a class not
>>> > yet
>>> > declared? ie is there a way to use either the lambda or string syntax
>>> > to
>>> > forward declare the fk constrains? Neither works for me. Using strings
>>> > yields:
>>> >
>>> > File "", line 2, in join_condition
>>> > File
>>> >
>>> > "/Users/alex/.pyenv/versions/api2/lib/python3.7/site-packages/sqlalchemy/sql/selectable.py",
>>> > line 964, in _join_condition
>>> > a, a_subset, b, consider_as_foreign_keys)
>>> > File
>>> >
>>> > "/Users/alex/.pyenv/versions/api2/lib/python3.7/site-packages/sqlalchemy/sql/selectable.py",
>>> > line 1021, in _joincond_scan_left_right
>>> > if nrte.table_name == b.name:
>>> > AttributeError: 'Join' object has no attribute 'name'
>>> >
>>> > and I can't get the lambda form to work.
>>> > I tried:
>>> > db.ForeignKeyConstraint((employee_id, year, home_fund_id),
>>> > ('FundEmployee.employee_id', 'FundEmployee.year',
>>> > 'FundEmployee.fund_id'))
>>>
>>> ForeignKeyConstraint can be fully declared with just strings and the
>>> referenced table and/or declarative class doesn't need to exist yet,
>>> see
>>> http://docs.sqlalchemy.org/en/latest/core/constraints.html#metadata-foreignkeys.
>>>That AttributeError doesn't seem to be raised by a
>>> ForeignK
Re: [sqlalchemy] ForeignKeyConstraint using Forward Declared Model
I tracked down the error on my side. Looks like I have to use the table
name rather than the model name (doh) in the string. That being said, there
may still be a bug in sqla where it tries to read the name off a join
(rather than a table).
That being said, any reason not to support the lambda syntax for
ForeignKeyConstraint rather than just the string syntax?
On Tuesday, September 4, 2018 at 10:43:13 PM UTC-4, Alex Rothberg wrote:
>
> You're right the error I posted is coming from somewhere else. I am trying
> to get a stripped down example. In the meantime, it looks like when I add
> the additional fk constraint, model.__mapper__.get_property(property_name)
> on a different model starts failing.
>
> File
> "/Users/alex/.pyenv/versions/api2/lib/python3.7/site-packages/marshmallow_sqlalchemy/convert.py"
> , line 151, in field_for
> prop = model.__mapper__.get_property(property_name)
> File
> "/Users/alex/.pyenv/versions/api2/lib/python3.7/site-packages/sqlalchemy/orm/mapper.py"
> , line 1923, in get_property
> configure_mappers()
> File
> "/Users/alex/.pyenv/versions/api2/lib/python3.7/site-packages/sqlalchemy/orm/mapper.py"
> , line 3033, in configure_mappers
> mapper._post_configure_properties()
> File
> "/Users/alex/.pyenv/versions/api2/lib/python3.7/site-packages/sqlalchemy/orm/mapper.py"
> , line 1832, in _post_configure_properties
> prop.init()
> File
> "/Users/alex/.pyenv/versions/api2/lib/python3.7/site-packages/sqlalchemy/orm/interfaces.py"
> , line 183, in init
> self.do_init()
> File
> "/Users/alex/.pyenv/versions/api2/lib/python3.7/site-packages/sqlalchemy/orm/relationships.py"
> , line 1656, in do_init
> self._setup_join_conditions()
> File
> "/Users/alex/.pyenv/versions/api2/lib/python3.7/site-packages/sqlalchemy/orm/relationships.py"
> , line 1731, in _setup_join_conditions
> can_be_synced_fn=self._columns_are_mapped
> File
> "/Users/alex/.pyenv/versions/api2/lib/python3.7/site-packages/sqlalchemy/orm/relationships.py"
> , line 1998, in __init__
> self._determine_joins()
> File
> "/Users/alex/.pyenv/versions/api2/lib/python3.7/site-packages/sqlalchemy/orm/relationships.py"
> , line 2082, in _determine_joins
> consider_as_foreign_keys=consider_as_foreign_keys
> File "", line 2, in join_condition
> File
> "/Users/alex/.pyenv/versions/api2/lib/python3.7/site-packages/sqlalchemy/sql/selectable.py"
> , line 964, in _join_condition
> a, a_subset, b, consider_as_foreign_keys)
> File
> "/Users/alex/.pyenv/versions/api2/lib/python3.7/site-packages/sqlalchemy/sql/selectable.py"
> , line 1021, in _joincond_scan_left_right
> if nrte.table_name == b.name:
> AttributeError: 'Join' object has no attribute 'name'
>
>
> On Tuesday, September 4, 2018 at 9:40:11 PM UTC-4, Mike Bayer wrote:
>>
>> On Tue, Sep 4, 2018 at 7:54 PM, Alex Rothberg
>> wrote:
>> > Is it possible to set up a `ForeignKeyConstraint` that uses a class not
>> yet
>> > declared? ie is there a way to use either the lambda or string syntax
>> to
>> > forward declare the fk constrains? Neither works for me. Using strings
>> > yields:
>> >
>> > File "", line 2, in join_condition
>> > File
>> >
>> "/Users/alex/.pyenv/versions/api2/lib/python3.7/site-packages/sqlalchemy/sql/selectable.py",
>>
>>
>> > line 964, in _join_condition
>> > a, a_subset, b, consider_as_foreign_keys)
>> > File
>> >
>> "/Users/alex/.pyenv/versions/api2/lib/python3.7/site-packages/sqlalchemy/sql/selectable.py",
>>
>>
>> > line 1021, in _joincond_scan_left_right
>> > if nrte.table_name == b.name:
>> > AttributeError: 'Join' object has no attribute 'name'
>> >
>> > and I can't get the lambda form to work.
>> > I tried:
>> > db.ForeignKeyConstraint((employee_id, year, home_fund_id),
>> > ('FundEmployee.employee_id', 'FundEmployee.year',
>> 'FundEmployee.fund_id'))
>>
>> ForeignKeyConstraint can be fully declared with just strings and the
>> referenced table and/or declarative class doesn't need to exist yet,
>> see
>> http://docs.sqlalchemy.org/en/latest/core/constraints.html#metadata-foreignkeys.
>>
>>
>>That AttributeError doesn't seem to be raised by a
>> ForeignKeyConstraint, looks like it's coming from orm.relatiionship or
>> something. Feel free to provide a more complete example of what
>> you're trying to do.
>>
>>
>> >
>> >
>> > --
>> > 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+...@googlegroups.com.
>> > To post to this group, send email to sqlal...@google
Re: [sqlalchemy] ForeignKeyConstraint using Forward Declared Model
You're right the error I posted is coming from somewhere else. I am trying
to get a stripped down example. In the meantime, it looks like when I add
the additional fk constraint, model.__mapper__.get_property(property_name)
on a different model starts failing.
File
"/Users/alex/.pyenv/versions/api2/lib/python3.7/site-packages/marshmallow_sqlalchemy/convert.py"
, line 151, in field_for
prop = model.__mapper__.get_property(property_name)
File
"/Users/alex/.pyenv/versions/api2/lib/python3.7/site-packages/sqlalchemy/orm/mapper.py"
, line 1923, in get_property
configure_mappers()
File
"/Users/alex/.pyenv/versions/api2/lib/python3.7/site-packages/sqlalchemy/orm/mapper.py"
, line 3033, in configure_mappers
mapper._post_configure_properties()
File
"/Users/alex/.pyenv/versions/api2/lib/python3.7/site-packages/sqlalchemy/orm/mapper.py"
, line 1832, in _post_configure_properties
prop.init()
File
"/Users/alex/.pyenv/versions/api2/lib/python3.7/site-packages/sqlalchemy/orm/interfaces.py"
, line 183, in init
self.do_init()
File
"/Users/alex/.pyenv/versions/api2/lib/python3.7/site-packages/sqlalchemy/orm/relationships.py"
, line 1656, in do_init
self._setup_join_conditions()
File
"/Users/alex/.pyenv/versions/api2/lib/python3.7/site-packages/sqlalchemy/orm/relationships.py"
, line 1731, in _setup_join_conditions
can_be_synced_fn=self._columns_are_mapped
File
"/Users/alex/.pyenv/versions/api2/lib/python3.7/site-packages/sqlalchemy/orm/relationships.py"
, line 1998, in __init__
self._determine_joins()
File
"/Users/alex/.pyenv/versions/api2/lib/python3.7/site-packages/sqlalchemy/orm/relationships.py"
, line 2082, in _determine_joins
consider_as_foreign_keys=consider_as_foreign_keys
File "", line 2, in join_condition
File
"/Users/alex/.pyenv/versions/api2/lib/python3.7/site-packages/sqlalchemy/sql/selectable.py"
, line 964, in _join_condition
a, a_subset, b, consider_as_foreign_keys)
File
"/Users/alex/.pyenv/versions/api2/lib/python3.7/site-packages/sqlalchemy/sql/selectable.py"
, line 1021, in _joincond_scan_left_right
if nrte.table_name == b.name:
AttributeError: 'Join' object has no attribute 'name'
On Tuesday, September 4, 2018 at 9:40:11 PM UTC-4, Mike Bayer wrote:
>
> On Tue, Sep 4, 2018 at 7:54 PM, Alex Rothberg > wrote:
> > Is it possible to set up a `ForeignKeyConstraint` that uses a class not
> yet
> > declared? ie is there a way to use either the lambda or string syntax to
> > forward declare the fk constrains? Neither works for me. Using strings
> > yields:
> >
> > File "", line 2, in join_condition
> > File
> >
> "/Users/alex/.pyenv/versions/api2/lib/python3.7/site-packages/sqlalchemy/sql/selectable.py",
>
>
> > line 964, in _join_condition
> > a, a_subset, b, consider_as_foreign_keys)
> > File
> >
> "/Users/alex/.pyenv/versions/api2/lib/python3.7/site-packages/sqlalchemy/sql/selectable.py",
>
>
> > line 1021, in _joincond_scan_left_right
> > if nrte.table_name == b.name:
> > AttributeError: 'Join' object has no attribute 'name'
> >
> > and I can't get the lambda form to work.
> > I tried:
> > db.ForeignKeyConstraint((employee_id, year, home_fund_id),
> > ('FundEmployee.employee_id', 'FundEmployee.year',
> 'FundEmployee.fund_id'))
>
> ForeignKeyConstraint can be fully declared with just strings and the
> referenced table and/or declarative class doesn't need to exist yet,
> see
> http://docs.sqlalchemy.org/en/latest/core/constraints.html#metadata-foreignkeys.
>
>
>That AttributeError doesn't seem to be raised by a
> ForeignKeyConstraint, looks like it's coming from orm.relatiionship or
> something. Feel free to provide a more complete example of what
> you're trying to do.
>
>
> >
> >
> > --
> > 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+...@googlegroups.com .
> > To post to this group, send email to sqlal...@googlegroups.com
> .
> > Visit this group at https://groups.google.com/group/sqlalchemy.
> > 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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Re: [sqlalchemy] ForeignKeyConstraint using Forward Declared Model
On Tue, Sep 4, 2018 at 7:54 PM, Alex Rothberg wrote:
> Is it possible to set up a `ForeignKeyConstraint` that uses a class not yet
> declared? ie is there a way to use either the lambda or string syntax to
> forward declare the fk constrains? Neither works for me. Using strings
> yields:
>
> File "", line 2, in join_condition
> File
> "/Users/alex/.pyenv/versions/api2/lib/python3.7/site-packages/sqlalchemy/sql/selectable.py",
> line 964, in _join_condition
> a, a_subset, b, consider_as_foreign_keys)
> File
> "/Users/alex/.pyenv/versions/api2/lib/python3.7/site-packages/sqlalchemy/sql/selectable.py",
> line 1021, in _joincond_scan_left_right
> if nrte.table_name == b.name:
> AttributeError: 'Join' object has no attribute 'name'
>
> and I can't get the lambda form to work.
> I tried:
> db.ForeignKeyConstraint((employee_id, year, home_fund_id),
> ('FundEmployee.employee_id', 'FundEmployee.year', 'FundEmployee.fund_id'))
ForeignKeyConstraint can be fully declared with just strings and the
referenced table and/or declarative class doesn't need to exist yet,
see
http://docs.sqlalchemy.org/en/latest/core/constraints.html#metadata-foreignkeys.
That AttributeError doesn't seem to be raised by a
ForeignKeyConstraint, looks like it's coming from orm.relatiionship or
something. Feel free to provide a more complete example of what
you're trying to do.
>
>
> --
> 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.
> Visit this group at https://groups.google.com/group/sqlalchemy.
> 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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Visit this group at https://groups.google.com/group/sqlalchemy.
For more options, visit https://groups.google.com/d/optout.
[sqlalchemy] ForeignKeyConstraint using Forward Declared Model
Is it possible to set up a `ForeignKeyConstraint` that uses a class not yet declared? ie is there a way to use either the lambda or string syntax to forward declare the fk constrains? Neither works for me. Using strings yields: File "", line 2, in join_condition File "/Users/alex/.pyenv/versions/api2/lib/python3.7/site-packages/sqlalchemy/sql/selectable.py" , line 964, in _join_condition a, a_subset, b, consider_as_foreign_keys) File "/Users/alex/.pyenv/versions/api2/lib/python3.7/site-packages/sqlalchemy/sql/selectable.py" , line 1021, in _joincond_scan_left_right if nrte.table_name == b.name: AttributeError: 'Join' object has no attribute 'name' and I can't get the lambda form to work. I tried: db.ForeignKeyConstraint((employee_id, year, home_fund_id), ( 'FundEmployee.employee_id', 'FundEmployee.year', 'FundEmployee.fund_id')) -- 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. Visit this group at https://groups.google.com/group/sqlalchemy. For more options, visit https://groups.google.com/d/optout.
