[sqlalchemy] Sanity checks
Is there a way to do some sanity check through thr SQLAlchemy. Check like - SQL Service is running, DB exists etc. --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups sqlalchemy group. To post to this group, send email to sqlalchemy@googlegroups.com To unsubscribe from this group, send email to sqlalchemy+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sqlalchemy?hl=en -~--~~~~--~~--~--~---
[sqlalchemy] Re: Convert type from dbapi description
On Dec 31 2008, 4:00 pm, Dusty Phillips buch...@gmail.com wrote: Hi there, I've been searching all over for a solution to this and have concluded that I must be doing it all wrong. I need to create a simple view of an arbitrary sql query result that includes the column names and types as a string (eg: integer, varchar, etc) as well as a summary of the row data. The problem is, I can't find the column type anywhere in the results! I thought the column type information would be in ResultProxy.context somewhere, but I can't find it. I also looked at the RowProxy, but it seems to only contain column names and values for each row. Assuming you have mapped classes to the tables, you can lookup the type through the class: Yourclass.c.COLUMNNAME.type The Proxyresult has an attribute, keys, that provides the column names. I hope this is close to what you want. The closest I've come is to use ResultProxy.cursor.cursor.description, which gives me a numeric identifier for the column type. The documentation seems to indicate that I can then use engine.dialect.dbapi_type_map to look up the type of the object. Unfortunately, this dictionary is empty, at least for postgres. I'm using sqlalchemy 0.5rc4, and it seems as though the type lookups may have changed since 0.4, but I can't figure out how its supposed to be done now. Thanks for any insight, Dusty --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups sqlalchemy group. To post to this group, send email to sqlalchemy@googlegroups.com To unsubscribe from this group, send email to sqlalchemy+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sqlalchemy?hl=en -~--~~~~--~~--~--~---
[sqlalchemy] Re: metadata.bind.echo = True
thats the SQL which SQLAlchemy is emitting. On Jan 1, 2009, at 2:31 AM, Ash wrote: Hello i am using sqlalchemy and to trace the query i use metadata.bind.echo = True but the o/p is very strange it gives the catalog queries. like INFO:sqlalchemy.engine.base.Engine.0x..4c: SELECT attname FROM pg_attribute WHERE attrelid = ( SELECT indexrelid FROM pg_index i WHERE i.indrelid = %(table)s AND i.indisprimary = 't') ORDER BY attnum n there r number of such query which hides the real query executed. Thanks in advance --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups sqlalchemy group. To post to this group, send email to sqlalchemy@googlegroups.com To unsubscribe from this group, send email to sqlalchemy+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sqlalchemy?hl=en -~--~~~~--~~--~--~---
[sqlalchemy] Re: Creating a custom type
I've been trying create the extension. Here is the code with a test:
http://paste.pocoo.org/show/97502/ - Extension
http://paste.pocoo.org/show/97503/ - Test
I need help to solve this little issue:
entity._descriptor.add_mapper_extension(BcryptMapperExtension())
AttributeError: 'str' object has no attribute '_descriptor'
Does could review the extension code?
On 22 dic 2008, 03:40, Michael Bayer mike...@zzzcomputing.com wrote:
oh, yeah for that recipe you'd have to use a flag on the mapper()
called batch=False. But don't use that, its inefficient.
So you can also create your type to detect a special value from the
mapper extension:
def before_insert(self, ):
instance.password = (instance.password, True)
class MyType(...):
...
def process_bind_param(self, value, dialect):
if isinstance(value, tuple):
return hasher.create(value[0], value[1])
But since this is really an instance-level business rule, a straight
descriptor and no custom type is definitely how I'd go on this one.
On Dec 21, 2008, at 6:47 PM, Kless wrote:
Thank you for detailed answer.
Here are any thoughts:
1) The before_insert was being omitted while I was inserting records
using an insert statement --that's logical because it was bypassing
the ORM--.
2) It's necessary to use *session.commit()* after of each record
because else it will have the value of 'instance.admin' of the last
record which will be used for all records to commit.
3) I believe that it isn't necessary use *after_insert*.
On 21 dic, 17:00, Michael Bayer mike...@zzzcomputing.com wrote:
On Dec 21, 2008, at 6:53 AM, Kless wrote:
I'm trying to build a custom type [1] to manage the bcrypt hashes
[2].
---
from bcrypt_wrap import password
from sqlalchemy import types
class Bcrypt(types.TypeDecorator):
Stores a bcrypt hash of a password.
impl = types.String #(60)
hasher = password.Password()
def process_bind_param(self, value, dialect):
return hasher.create(value)
---
And I've any doubts:
1) Since that the hash length is always 60, is there that use the
next?
impl = types.String(60)
2) The bcryptWrap API [3] (line 53) lets call to 'create' with
arguments 'cost' and 'admin' (boolean). Then,
a) I would that the cost could be passed from the column
definition,
i.e.
password = sqlalchemy.Column(types.Bcrypt, cost=12)
or
password = sqlalchemy.Column(types.Bcrypt(cost=12))
b) This would be more hard, but I would to pass the 'admin'
argument
when an object is created
u = model.User()
u.login = u'foo'
u.password = u'bar'
u.admin = True
And sou could be call:
return hasher.create(value, admin=True)
the TypeDecorator's __init__ method just calls the impl class
immediately, so the best approach is like:
class Bcrypt(types.TypeDecorator):
Stores a bcrypt hash of a password.
impl = types.String
hasher = password.Password()
def __init__(self, cost):
self.cost = cost
types.TypeDecorator.__init__(self, 60)
def process_bind_param(self, value, dialect):
return hasher.create(value)
then you can instantate like:
Column('foo', Bcrypt(cost=12))
For b, the type object and the ExecutionContext which ultimately
calls
its process_bind_param method are unaware of the ORM or the ORM-
specific context in which its called during INSERT/UPDATE. If you
wanted to keep the logic within your type like that you'd have to
integrate to a thread-local variable that is configured within an ORM
plugin, something like:
hasher_status = threading.local()
class MyMapperExt(MapperExtension):
def before_insert(self, ...):
hasher_status.admin = instance.admin
def after_insert(self, ...)
del hasher_status.admin
mapper(MyClass, table, ext=MyMapperExt)
class Bcrypt(types.TypeDecorator):
...
def process_bind_param(self, value, dialect):
return hasher.create(value, getattr(hasher_status, 'admin',
False))
Alternatively, you could keep the logic within the ORM using either a
valdiator or a descriptor, as described
athttp://www.sqlalchemy.org/docs/05/mappers.html#changing-attribute-beh
...
. It depends on if you'd like your Bcrypt type to work with direct
SQL expression language use or not.
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[sqlalchemy] LucidDB - open RDBMS with advanced features
Here there is a presentation [1] over LucidDB [2], a new open-source RDBMS with advanced features and greater performance than MySQL. Besides column-store, other features covered include bitmap indexing, hash join/aggregation, page-level multiversioning, intelligent prefetch, star-join optimization, connectivity, and extensibility. [1] http://en.oreilly.com/oscon2008/public/schedule/detail/2781 [2] http://www.luciddb.org/ --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups sqlalchemy group. To post to this group, send email to sqlalchemy@googlegroups.com To unsubscribe from this group, send email to sqlalchemy+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sqlalchemy?hl=en -~--~~~~--~~--~--~---
[sqlalchemy] Re: Creating a custom type
mapper extensions are established during the mapper() phase:
mapper(someclass, sometable, extension=BycryptMapperExtension())
On Jan 1, 2009, at 1:35 PM, Kless wrote:
I've been trying create the extension. Here is the code with a test:
http://paste.pocoo.org/show/97502/ - Extension
http://paste.pocoo.org/show/97503/ - Test
I need help to solve this little issue:
entity._descriptor.add_mapper_extension(BcryptMapperExtension())
AttributeError: 'str' object has no attribute '_descriptor'
Does could review the extension code?
On 22 dic 2008, 03:40, Michael Bayer mike...@zzzcomputing.com wrote:
oh, yeah for that recipe you'd have to use a flag on the mapper()
called batch=False.But don't use that, its inefficient.
So you can also create your type to detect a special value from the
mapper extension:
def before_insert(self, ):
instance.password = (instance.password, True)
class MyType(...):
...
def process_bind_param(self, value, dialect):
if isinstance(value, tuple):
return hasher.create(value[0], value[1])
But since this is really an instance-level business rule, a straight
descriptor and no custom type is definitely how I'd go on this one.
On Dec 21, 2008, at 6:47 PM, Kless wrote:
Thank you for detailed answer.
Here are any thoughts:
1) The before_insert was being omitted while I was inserting records
using an insert statement --that's logical because it was bypassing
the ORM--.
2) It's necessary to use *session.commit()* after of each record
because else it will have the value of 'instance.admin' of the last
record which will be used for all records to commit.
3) I believe that it isn't necessary use *after_insert*.
On 21 dic, 17:00, Michael Bayer mike...@zzzcomputing.com wrote:
On Dec 21, 2008, at 6:53 AM, Kless wrote:
I'm trying to build a custom type [1] to manage the bcrypt hashes
[2].
---
from bcrypt_wrap import password
from sqlalchemy import types
class Bcrypt(types.TypeDecorator):
Stores a bcrypt hash of a password.
impl = types.String #(60)
hasher = password.Password()
def process_bind_param(self, value, dialect):
return hasher.create(value)
---
And I've any doubts:
1) Since that the hash length is always 60, is there that use the
next?
impl = types.String(60)
2) The bcryptWrap API [3] (line 53) lets call to 'create' with
arguments 'cost' and 'admin' (boolean). Then,
a) I would that the cost could be passed from the column
definition,
i.e.
password = sqlalchemy.Column(types.Bcrypt, cost=12)
or
password = sqlalchemy.Column(types.Bcrypt(cost=12))
b) This would be more hard, but I would to pass the 'admin'
argument
when an object is created
u = model.User()
u.login = u'foo'
u.password = u'bar'
u.admin = True
And sou could be call:
return hasher.create(value, admin=True)
the TypeDecorator's __init__ method just calls the impl class
immediately, so the best approach is like:
class Bcrypt(types.TypeDecorator):
Stores a bcrypt hash of a password.
impl = types.String
hasher = password.Password()
def __init__(self, cost):
self.cost = cost
types.TypeDecorator.__init__(self, 60)
def process_bind_param(self, value, dialect):
return hasher.create(value)
then you can instantate like:
Column('foo', Bcrypt(cost=12))
For b, the type object and the ExecutionContext which ultimately
calls
its process_bind_param method are unaware of the ORM or the ORM-
specific context in which its called during INSERT/UPDATE. If you
wanted to keep the logic within your type like that you'd have to
integrate to a thread-local variable that is configured within an
ORM
plugin, something like:
hasher_status = threading.local()
class MyMapperExt(MapperExtension):
def before_insert(self, ...):
hasher_status.admin = instance.admin
def after_insert(self, ...)
del hasher_status.admin
mapper(MyClass, table, ext=MyMapperExt)
class Bcrypt(types.TypeDecorator):
...
def process_bind_param(self, value, dialect):
return hasher.create(value, getattr(hasher_status,
'admin',
False))
Alternatively, you could keep the logic within the ORM using
either a
valdiator or a descriptor, as described
athttp://www.sqlalchemy.org/docs/05/mappers.html#changing-attribute-beh
...
. It depends on if you'd like your Bcrypt type to work with
direct
SQL expression language use or not.
--~--~-~--~~~---~--~~
You received this message because you are subscribed to the Google Groups
sqlalchemy group.
To post to this group, send email to sqlalchemy@googlegroups.com
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sqlalchemy+unsubscr...@googlegroups.com
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[sqlalchemy] Re: Creating a custom type
It's being passed from the IsBcrypt constructor, so: entity._descriptor.add_mapper_extension(BcryptMapperExtension()) On 1 ene, 19:48, Michael Bayer mike...@zzzcomputing.com wrote: mapper extensions are established during the mapper() phase: mapper(someclass, sometable, extension=BycryptMapperExtension()) On Jan 1, 2009, at 1:35 PM, Kless wrote: I've been trying create the extension. Here is the code with a test: http://paste.pocoo.org/show/97502/- Extension http://paste.pocoo.org/show/97503/- Test I need help to solve this little issue: entity._descriptor.add_mapper_extension(BcryptMapperExtension()) AttributeError: 'str' object has no attribute '_descriptor' Does anybody could review the extension code? --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups sqlalchemy group. To post to this group, send email to sqlalchemy@googlegroups.com To unsubscribe from this group, send email to sqlalchemy+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sqlalchemy?hl=en -~--~~~~--~~--~--~---
[sqlalchemy] Re: Creating a custom type
I just see that will be by a problem of change in API AttributeError: 'str' object has no attribute '_descriptor' Kless ha escrito: It's being passed from the IsBcrypt constructor, so: entity._descriptor.add_mapper_extension(BcryptMapperExtension()) On 1 ene, 19:48, Michael Bayer mike...@zzzcomputing.com wrote: mapper extensions are established during the mapper() phase: mapper(someclass, sometable, extension=BycryptMapperExtension()) On Jan 1, 2009, at 1:35 PM, Kless wrote: I've been trying create the extension. Here is the code with a test: �http://paste.pocoo.org/show/97502/- Extension �http://paste.pocoo.org/show/97503/- Test I need help to solve this little issue: entity._descriptor.add_mapper_extension(BcryptMapperExtension()) AttributeError: 'str' object has no attribute '_descriptor' Does anybody could review the extension code? --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups sqlalchemy group. To post to this group, send email to sqlalchemy@googlegroups.com To unsubscribe from this group, send email to sqlalchemy+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sqlalchemy?hl=en -~--~~~~--~~--~--~---
[sqlalchemy] Re: Creating a custom type
Kless wrote: I just see that will be by a problem of change in API AttributeError: 'str' object has no attribute '_descriptor' As I indicated to you over on the Elixir list, you seem to have used the Elixir encryption extension as a starting point. The _descriptor and the concept of an entity are Elixir concepts, not SQLAlchemy concepts. You need to base your work on other mapper extensions, not on the Elixir extension, which is designed to only work with Elixir models, not plain-SQLAlchemy models. I'd suggest starting over, and using the following documentation references: Mapper Extension API reference: http://tinyurl.com/8wfkgl Applying Mapper Extensions: http://tinyurl.com/7a3b5c Good luck. -- Jonathan LaCour http://cleverdevil.org --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups sqlalchemy group. To post to this group, send email to sqlalchemy@googlegroups.com To unsubscribe from this group, send email to sqlalchemy+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sqlalchemy?hl=en -~--~~~~--~~--~--~---
[sqlalchemy] Re: Creating a custom type
Thanks. This was your message on the Elixir list: It looks to me like you are using SQLAlchemy without Elixir, and therefore this isn't the proper place to be asking this question. You should ask over on the SQLAlchemy mailing list. If you would like help creating an elixir extension, I can help you with that here. Good luck. On 1 ene, 21:01, Jonathan LaCour jonathan-li...@cleverdevil.org wrote: Kless wrote: I just see that will be by a problem of change in API AttributeError: 'str' object has no attribute '_descriptor' As I indicated to you over on the Elixir list, you seem to have used the Elixir encryption extension as a starting point. The _descriptor and the concept of an entity are Elixir concepts, not SQLAlchemy concepts. You need to base your work on other mapper extensions, not on the Elixir extension, which is designed to only work with Elixir models, not plain-SQLAlchemy models. I'd suggest starting over, and using the following documentation references: Mapper Extension API reference:http://tinyurl.com/8wfkgl Applying Mapper Extensions:http://tinyurl.com/7a3b5c Good luck. -- Jonathan LaCourhttp://cleverdevil.org --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups sqlalchemy group. To post to this group, send email to sqlalchemy@googlegroups.com To unsubscribe from this group, send email to sqlalchemy+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sqlalchemy?hl=en -~--~~~~--~~--~--~---
[sqlalchemy] Re: schema inspection api
On Monday 29 December 2008 13:31:02 Michael Bayer wrote: [...] There are already a lot of tools that build forms and such based on tables which use the existing reflection capabilities, so what's currently available is probably sufficient for your needs. Michael, Do you by any chance have a list of these tools? I'd like to look at them. Thank you, NicoEchániz. --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups sqlalchemy group. To post to this group, send email to sqlalchemy@googlegroups.com To unsubscribe from this group, send email to sqlalchemy+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sqlalchemy?hl=en -~--~~~~--~~--~--~---
[sqlalchemy] Re: schema inspection api
sure we have: http://code.google.com/p/dbsprockets/ http://code.google.com/p/formalchemy/ http://www.sprox.org/ to be fair, sprox seems to be a reorganization of dbsprokets. On Jan 1, 2009, at 6:36 PM, Nicolas Echaniz wrote: On Monday 29 December 2008 13:31:02 Michael Bayer wrote: [...] There are already a lot of tools that build forms and such based on tables which use the existing reflection capabilities, so what's currently available is probably sufficient for your needs. Michael, Do you by any chance have a list of these tools? I'd like to look at them. Thank you, NicoEchániz. --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups sqlalchemy group. To post to this group, send email to sqlalchemy@googlegroups.com To unsubscribe from this group, send email to sqlalchemy+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sqlalchemy?hl=en -~--~~~~--~~--~--~---
[sqlalchemy] How to identify a transaction that has already begun
Hi All, I configure a session (from elixir) using this code: session = sqlalchemy.orm.scoped_session( sqlalchemy.orm.sessionmaker( autoflush=False, autocommit=False ) ) Is there any way to identify whether the transaction has already begun to avoid exception? -- Salam, -Jaimy Azle Great new ideas usually come from very small teams... don't give up so easily. -- John Kaster --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups sqlalchemy group. To post to this group, send email to sqlalchemy@googlegroups.com To unsubscribe from this group, send email to sqlalchemy+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sqlalchemy?hl=en -~--~~~~--~~--~--~---
