Re: [sqlalchemy] How to refer to columns whose names begin with a number when autoloading?
Thanks. That worked, too.
On Tuesday, April 13, 2021 at 8:46:34 AM UTC-5 Mike Bayer wrote:
> the next section at
> https://docs.sqlalchemy.org/en/14/orm/mapping_columns.html#automating-column-naming-schemes-from-reflected-tables
>
> shows how to automate intercepting of reflected columns, so you could do
> this:
>
> from sqlalchemy import event
>
> @event.listens_for(metadata, "column_reflect")
> def column_reflect(inspector, table, column_info):
> entries = {
> "1st": "first",
> "2nd": "second",
> "3rd": "third",
> "4th": "fourth"
> }
> for prefix in entries:
> if prefix in column["name"]:
> column["key"] = column["name"].replace(prefix, entries[prefix])
> break
>
>
> class Student(Model):
> __table__ = Table("Students", metadata, autoload=True,
> autoload_with=engine)
>
>
>
>
> On Tue, Apr 13, 2021, at 8:48 AM, r...@rosenfeld.to wrote:
>
> Thanks for the documentation. Sorry, but I'm not certain how to apply
> that in my case. Since I am mapping to an existing table, how could I
> reference the object attribute with an illegal name in Python? Do I
> combine getattr with the documentation as below?
>
> class Student(Model):
> __table__ = Table("Students", metadata, autoload=True,
> autoload_with=engine)
> first_period = getattr(__table__.c, "1st_period")
>
> Thanks,
> Rob
> On Monday, April 12, 2021 at 11:17:59 PM UTC-5 Mike Bayer wrote:
>
>
> besides the idea of using getattr(), as these are object attributes it's
> probably a good idea to name them differently from those columns. See the
> docs at
> https://docs.sqlalchemy.org/en/14/orm/mapping_columns.html#naming-columns-distinctly-from-attribute-names
>
> for strategies on how to achieve this.
>
>
> On Mon, Apr 12, 2021, at 12:29 AM, Rob Rosenfeld wrote:
>
> Hi All,
>
> I'm using SQLAlchemy to access a legacy MSSQL database. I'm using the
> autoload feature to load the schema from the database.
>
> In this example I'd like to read data out of the column named "1st_period"
> in the database. The following query shows the SQL I'd need. But trying
> to access a property named "1st_period" yields a SyntaxError
>
> Thanks,
> Rob
>
> SELECT TOP 10 [1st_period] FROM Students;
>
> class Student(Model):
> __table__ = Table("Students", metadata, autoload=True,
> autoload_with=engine)
>
>
> @property
> def first_period(self):
> return self.1st_period
>
>
>
>
> --
> 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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> .
>
>
>
> --
> 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 -
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] How to refer to columns whose names begin with a number when autoloading?
Thanks for the documentation. Sorry, but I'm not certain how to apply that
in my case. Since I am mapping to an existing table, how could I reference
the object attribute with an illegal name in Python? Do I combine getattr
with the documentation as below?
class Student(Model):
__table__ = Table("Students", metadata, autoload=True,
autoload_with=engine)
first_period = getattr(__table__.c, "1st_period")
Thanks,
Rob
On Monday, April 12, 2021 at 11:17:59 PM UTC-5 Mike Bayer wrote:
> besides the idea of using getattr(), as these are object attributes it's
> probably a good idea to name them differently from those columns. See the
> docs at
> https://docs.sqlalchemy.org/en/14/orm/mapping_columns.html#naming-columns-distinctly-from-attribute-names
>
> for strategies on how to achieve this.
>
>
> On Mon, Apr 12, 2021, at 12:29 AM, Rob Rosenfeld wrote:
>
> Hi All,
>
> I'm using SQLAlchemy to access a legacy MSSQL database. I'm using the
> autoload feature to load the schema from the database.
>
> In this example I'd like to read data out of the column named "1st_period"
> in the database. The following query shows the SQL I'd need. But trying
> to access a property named "1st_period" yields a SyntaxError
>
> Thanks,
> Rob
>
> SELECT TOP 10 [1st_period] FROM Students;
>
> class Student(Model):
> __table__ = Table("Students", metadata, autoload=True,
> autoload_with=engine)
>
>
> @property
> def first_period(self):
> return self.1st_period
>
>
>
>
> --
> 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
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> To unsubscribe from this group and stop receiving emails from it, send an
> email to sqlalchemy+...@googlegroups.com.
> To view this discussion on the web visit
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>
>
> .
>
>
>
--
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] How to refer to columns whose names begin with a number when autoloading?
Yep. That seems fine. Thanks.
SQLAlchemy doesn't escape or quote the name. I checked using
inspection = inspect(Student)
return [c_attr.key for c_attr in inspection.mapper.column_attrs]
On Monday, April 12, 2021 at 5:55:07 AM UTC-5 Richard Damon wrote:
> On 4/12/21 12:29 AM, Rob Rosenfeld wrote:
> > Hi All,
> >
> > I'm using SQLAlchemy to access a legacy MSSQL database. I'm using
> > the autoload feature to load the schema from the database.
> >
> > In this example I'd like to read data out of the column named
> > "1st_period" in the database. The following query shows the SQL I'd
> > need. But trying to access a property named "1st_period" yields a
> > SyntaxError
> >
> > Thanks,
> > Rob
> >
> > SELECTTOP 10[1st_period] FROM Students;
> >
> > class Student(Model):
> > __table__ = Table("Students", metadata, autoload=True,
> > autoload_with=engine)
> >
> > @property
> > def first_period(self):
> > return self.1st_period
>
>
> Have you tried using getattr? That might work (if SQLAlchemy isn't doing
> something to quote the name to make a valid version.
>
> getattr(self, '1st_period') would be the equivalent of self.1st_period,
> but not have the name parsed by Python.
>
> --
> Richard Damon
>
>
--
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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