[sqlalchemy] Re: checking in
> If not I wonder why messages aren't arriving in my INBOX. Check your settings for this group. If you do not see the option on the menu, try visiting https://groups.google.com/g/sqlalchemy/membership Google sometimes has a product change de-selects the email delivery option. Sometimes users de-select email delivery and forget about that too. On Monday, June 14, 2021 at 5:25:47 PM UTC-4 rshe...@appl-ecosys.com wrote: > I've not worked with SQLAlchemy for several years but now want to use it in > a couple of applications. I've not seen messages on this maillist for a > very > long time so I tried subscribing and learned that I'm still subscribed. > > Am I the only one on this list now? > > If not I wonder why messages aren't arriving in my INBOX. > > Rich > -- 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 view this discussion on the web visit https://groups.google.com/d/msgid/sqlalchemy/b9f2ec03-8dff-4796-b1a3-2efc4409729en%40googlegroups.com.
[sqlalchemy] Re: checking script validity
Not quite related to sqlalchemy, but if you want a one-time check, check out sqlfiddle http://sqlfiddle.com/. On Friday, August 30, 2013 8:30:09 AM UTC+3, monosij...@gmail.com wrote: Hello - Not very familiar with sqlalchemy yet ... Is there a way to check if a script I have generated (not using sqlalchemy) is valid for a particular DBMS (Postgres, MySQL, etc.) It would be an ANSI SQL script and there is module ansisql but not able to find where I can check a script for validity against a particular DBMS (Postgres). I would need to validate a create table script as well index creation script and foreign key constraint script. Thank you. -- 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 http://groups.google.com/group/sqlalchemy. For more options, visit https://groups.google.com/groups/opt_out.
[sqlalchemy] Re: Checking internals of query object
I'm considering just checking for terms in the sql statement produced from str(query). That way I don't have to muddle with the internals of Query. However, I do introduce table and column names from the DB into my test code as strings, which of course defeats one of the reasons for using SA. However, this is *just* test code, and when I change column names in the DB and the tests fail, I''l change the tests. The alternative would to be to change the tests when the internals of Query change, which I don't have as much control over. Thanks for the insight. On Aug 27, 10:58 am, Michael Bayer mike...@zzzcomputing.com wrote: On Aug 27, 1:24 pm, Bryan bryanv...@gmail.com wrote: I am writing a function that adds particular columns and groupings to a query based on some options. I am trying to write some unit tests for the function, and would like to check that the correct columns are being added/grouped. Give a query like: q = session.query(Employee.firstName, Employee.lastName) How can I check later that the query object has included Employee.firstName in the output columns? for output columns, we have recently added a method for this purpose as of version 0.6.3: http://www.sqlalchemy.org/docs/reference/orm/query.html#sqlalchemy.or... I'm using it successfully in a library that converts Query objects into Excel spreadsheets with xlwt. Similarly, how can I check, for instance, that the query object is grouping on Employee.lastName? stuff like that is semi-private but relatively stable, most are available by names like query._group_by, query._order_by, query._criterion. If you look at the top of the Query class (the source), they are all defaulted at the class level. Semi-private because I really don't want to push things like that to be first class accessors until we are super certain nothing is changing there. -- You received this message because you are subscribed to the Google Groups sqlalchemy group. To post to this group, send email to sqlalch...@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: checking for C extensions at runtime
On Jul 16, 11:56 am, David Gardner dgard...@creatureshop.com wrote: I'm actually not sure, I did a bit of googling and couldn't really find much. Pep 386 talks about version comparison in distutils:http://www.python.org/dev/peps/pep-0386/#id10 As for scratching my itch it wouldn't have to be in the __version__ string, I was just wondering how I would check if the SQLAlchemy on a system had the C extensions enabled on it or not. at the moment, I'd probably try importing cprocessors from sqlalchemy, or just look at sqlalchemy.processors.str_to_date.__file__. We haven't put any official method for this in yet and also we'd like to have the C extensions turned on by default at some point. On 07/15/2010 01:40 PM, Michael Bayer wrote: I was wondering if there was a way to check at runtime if the C extensions were built with SQLAlchemy? If not I was wondering if you would consider adding something to the __version__ string? is there some guideline for the format on that ? -- David Gardner Pipeline Tools Programmer Jim Henson Creature Shop dgard...@creatureshop.com -- You received this message because you are subscribed to the Google Groups sqlalchemy group. To post to this group, send email to sqlalch...@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: checking a relationship exists
thanks - but how does that query specify a town? It seems like that would just return true if the current user had any town relationships? Or am I reading it wrong? On Sep 19, 5:46 pm, Michael Bayer mike...@zzzcomputing.com wrote: On Sep 19, 2009, at 11:41 AM, joeformd wrote: When we tried that it made a sql query to get all the towns (towns are loaded lazily) - that could be an awful lot of information, so this would be a much faster query so, the most succinct (and efficient) query of all is session.scalar(exists().where(user_towns.c.user_id==current_user.id)) should return True/False right back On Sep 19, 4:33 pm, Michael Bayer mike...@zzzcomputing.com wrote: On Sep 19, 2009, at 10:19 AM, joeformd wrote: Thanks for the speedy response Michael, we came up with this: current_user_has_town = bool(session.query(User).filter (User.id==current_user.id).filter(User.towns.contains (current_user)).count()) which maybe has slightly clearer intent? if you already have the current_user, why not just say town in current_user.towns --~--~-~--~~~---~--~~ 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: checking a relationship exists
Thanks for the speedy response Michael, we came up with this: current_user_has_town = bool(session.query(User).filter (User.id==current_user.id).filter(User.towns.contains (current_user)).count()) which maybe has slightly clearer intent? --~--~-~--~~~---~--~~ 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: checking a relationship exists
On Sep 19, 2009, at 10:19 AM, joeformd wrote: Thanks for the speedy response Michael, we came up with this: current_user_has_town = bool(session.query(User).filter (User.id==current_user.id).filter(User.towns.contains (current_user)).count()) which maybe has slightly clearer intent? if you already have the current_user, why not just say town in current_user.towns --~--~-~--~~~---~--~~ 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: checking a relationship exists
When we tried that it made a sql query to get all the towns (towns are loaded lazily) - that could be an awful lot of information, so this would be a much faster query On Sep 19, 4:33 pm, Michael Bayer mike...@zzzcomputing.com wrote: On Sep 19, 2009, at 10:19 AM, joeformd wrote: Thanks for the speedy response Michael, we came up with this: current_user_has_town = bool(session.query(User).filter (User.id==current_user.id).filter(User.towns.contains (current_user)).count()) which maybe has slightly clearer intent? if you already have the current_user, why not just say town in current_user.towns --~--~-~--~~~---~--~~ 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: checking a relationship exists
On Sep 19, 2009, at 11:41 AM, joeformd wrote: When we tried that it made a sql query to get all the towns (towns are loaded lazily) - that could be an awful lot of information, so this would be a much faster query so, the most succinct (and efficient) query of all is session.scalar(exists().where(user_towns.c.user_id==current_user.id)) should return True/False right back On Sep 19, 4:33 pm, Michael Bayer mike...@zzzcomputing.com wrote: On Sep 19, 2009, at 10:19 AM, joeformd wrote: Thanks for the speedy response Michael, we came up with this: current_user_has_town = bool(session.query(User).filter (User.id==current_user.id).filter(User.towns.contains (current_user)).count()) which maybe has slightly clearer intent? if you already have the current_user, why not just say town in current_user.towns --~--~-~--~~~---~--~~ 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: checking a relationship exists
On Sep 18, 2009, at 7:44 PM, joeformd wrote:
Is there a simple way in SQLA to check if a relationship exists
between two rows in a many-to-many situation, where the relationship
is defined using another table?
eg. the join table might look like this:
user_towns = Table('user_towns', Base.metadata,
Column('user_id', Integer, ForeignKey('users.id')),
Column('town_id', Integer, ForeignKey('towns.id'))
)
to check if a relationship exists, the SQL would be fairly simple,
with no joins required (is there a row in this table where user.id =
user_id and town.id = town_id)
Is there a simple way of asking this using SQLA, with the query
syntax?
the simplest would be query(User.id).join(User.towns).filter
(User.id==uid).filter(Town.id==tid).
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[sqlalchemy] Re: checking if a column is in a list
On Jan 21, 2009, at 7:46 PM, Jack Stahl wrote:
Hello,
I've got a few SQL interfaces where I'd like to change my query
based on the columns required by the client. For example, in one
situation, I only join against my User table if my client requires a
photo id:
# cols is the list of columns the client would like selected
if User.c.photo_id in cols:
table = table.join(User.table)
In another situation, I'd like to include the flags column in the
query even if the client ask for it
if not cols:
cols = [cls]
elif not (cls.c.flags in cols):
# ensure flags are there so we can add is_active
cols.append(cls.c.flags)
However, my tests for membership pass regardless of whether column
is actually in the list cols. That is,
Column('flags', BitField(), table=foo_table) in [Column('foo',
String(length=84, convert_unicode=False, assert_unicode=None),
table=foo_table), Column('bar', Text(length=None,
convert_unicode=False, table=foo_table)]
evaluates to True
Is the == operator not properly implemented for SQLAlchemy Columns?
(I'm using version 0.42)
it is not properly implemented in the sense that it does not return
True or False, but if you''ve used SQLalchemy, you'd know that we
redefine the == operator to return ClauseElement objects. That's
why you can say somecolumn==5 and get an expression from it.
So you cannot use the in operator to search for a Column object in a
list. The solution however is simple. Use a set() instead, where the
objects will be compared based on the return value of __hash__() which
results in an object identity comparison.
if User.c.photo_id in set(cols):
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[sqlalchemy] Re: checking if a column is in a list
Thanks Michael!
Properly was a poor choice of words on my part. Yes, of course, == is
overloaded to make where (etc) clauses pretty, I just didn't put two and two
together.
--jack
On Wed, Jan 21, 2009 at 5:38 PM, Michael Bayer mike...@zzzcomputing.comwrote:
On Jan 21, 2009, at 7:46 PM, Jack Stahl wrote:
Hello,
I've got a few SQL interfaces where I'd like to change my query
based on the columns required by the client. For example, in one
situation, I only join against my User table if my client requires a
photo id:
# cols is the list of columns the client would like selected
if User.c.photo_id in cols:
table = table.join(User.table)
In another situation, I'd like to include the flags column in the
query even if the client ask for it
if not cols:
cols = [cls]
elif not (cls.c.flags in cols):
# ensure flags are there so we can add is_active
cols.append(cls.c.flags)
However, my tests for membership pass regardless of whether column
is actually in the list cols. That is,
Column('flags', BitField(), table=foo_table) in [Column('foo',
String(length=84, convert_unicode=False, assert_unicode=None),
table=foo_table), Column('bar', Text(length=None,
convert_unicode=False, table=foo_table)]
evaluates to True
Is the == operator not properly implemented for SQLAlchemy Columns?
(I'm using version 0.42)
it is not properly implemented in the sense that it does not return
True or False, but if you''ve used SQLalchemy, you'd know that we
redefine the == operator to return ClauseElement objects. That's
why you can say somecolumn==5 and get an expression from it.
So you cannot use the in operator to search for a Column object in a
list. The solution however is simple. Use a set() instead, where the
objects will be compared based on the return value of __hash__() which
results in an object identity comparison.
if User.c.photo_id in set(cols):
--~--~-~--~~~---~--~~
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[sqlalchemy] Re: Checking active transactions
On Feb 22, 2008, at 5:29 AM, Christoph Zwerschke wrote: In TurboGears 1, requests are encapsulated between a session.begin() and session.commit() call (or session.rollback(), if there was an error). Starting with SA 0.4.3, the commit() raises an exception if the transaction has been already rolled back in the request (explicitly or due to an error). So TurboGears needs to check whether the transaction is active before the session.commit() call. We currently do this by storing the transaction as the return value of session.begin() and then checking transaction.is_active (or transaction.session.transaction for earlier SA versions). This gets complicated since the transaction may be restarted during a request and can change. So I think it would be handy to tell directly from the session whether the transaction is active or not. We are using *scoped* sessions in TruboGears, and the problem is that the transaction attribute is not available in ScopedSessions, so I can not check for session.transaction.is_active. I can get the original Session by calling session, so session().transaction.is_active would work, but it does not feel right. I guess it is by intent that the session attributes are not visible in scoped sessions. So how about adding a property is_active to the Session that would call session.transaction.is_active? Then you could do: if session.is_active: session.commit() thats fine...but also why cant you just say try: session.commit() except: session.rollback(); raise ? --~--~-~--~~~---~--~~ 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 [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sqlalchemy?hl=en -~--~~~~--~~--~--~---
[sqlalchemy] Re: Checking active transactions
Michael Bayer schrieb: thats fine...but also why cant you just say try: session.commit() except: session.rollback(); raise ? This would raise an error when the session is already inactive. I don't want an error in this case. On the other hand, if I remove the raise statement, then errors on commit would be swallowed. I thought about catching only InvalidRequestError, but this might also catch too much. -- Christoph --~--~-~--~~~---~--~~ 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 [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sqlalchemy?hl=en -~--~~~~--~~--~--~---
[sqlalchemy] Re: checking the sql string.
On May 27, 2007, at 4:23 PM, SamDonaldson wrote:
How do I look to see what sql is being constructed in the query
object? So if I have something like:
q = query.session(User)
q = q.add_column()
q = q.group_by(.).select()
How do I check what sql string has been constructed in q?
the Select object is returned by query.compile(). but also you can
just enable logging of 'sqlalchemy.engine' or use echo=True on
create_engine() which may be more expedient.
Also, say I want to do a group by a particular column name on the User
table and I have two aggregates, sum, and count? How do I add these
two columns to q? Do I just call add_column twice? It's not working,
I'm getting an empty result set.
q = query.session(User)
q = q.add_column(func.sum(User.c.id).label('sum'))
q = q.add_column(func.count(User.c.id).label('count'))
q = q.group_by([User.c.blah]).select()
I'm getting an empty result set. What exactly does label do here?
its going to use the AS keyword to apply a column label, such as:
select users.id as users_id, users.name as users_name, sum(users.id)
as sum, count(users.id) as count
FROM users GROUP BY users.blah
take a look what its generating and play around with the resulting
SQL manually to get an idea about what will return results.
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