Re: [sqlalchemy] Updating user interface after rollback (using after_rollback SessionExtension?)
Hi Michael, On Mon, 2011-08-01 at 14:18 -0400, Michael Bayer wrote: The Session's default behavior is to expire fully the state present after a rollback occurs. The next access of any attribute will guaranteed pull fresh from the DB in a new transaction. I'm assuming you know this, and that there is something additional here you're looking for, like an event to the GUI to actually re-access the attributes, or something. Exactly. A surprise for me.Yes the after_rollback() seems to only fire after an actual database rollback. This is a bug in that there is no way to catch soft rollbacks. I can't change the event, as it is integral in transactional extensions like that supplied for Zope; a new one will have to be added and the docs for after_rollback() will need to be updated. Actually I expected after_rollback to fire only after an actual DB rollback. Or did I misinterpret the errors in that the rollback came before a flush to the database and therefore no actual reload from the database would be needed? Ticket #2241 is added for this and is completed. You can now use the 0.7 tip and use the after_soft_rollback() event in conjunction with the is_active flag: @event.listens_for(Session, after_soft_rollback) def do_something(session, previous_transaction): if session.is_active: session.execute(select * from some_table) I looked at the is_active flag in SQLAlchemy 0.6.8 already and I think I can only use it with autocommit disabled. Unfortunately I use autocommit=True. I know that's a bad choice from the SQLAlchemy point of view. The reason why I am using it is that I want to avoid to keep the database locked over a long time, as this makes our background processes fail (OperationalError: Database is locked). I am a victim of the limitations of SQLite here :-( Perhaps after the current stabilization phase, I will move to SA 0.7 and autocommit=False. I am not sure about the latter though. Thanks and Greetings, Torsten -- DYNAmore Gesellschaft fuer Ingenieurdienstleistungen mbH Torsten Landschoff Office Dresden Tel: +49-(0)351-4519587 Fax: +49-(0)351-4519561 mailto:torsten.landsch...@dynamore.de http://www.dynamore.de Registration court: Mannheim, HRB: 109659, based in Karlsruhe, Managing director: Prof. Dr. K. Schweizerhof, Dipl.-Math. U. Franz -- 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.
Re: [sqlalchemy] Relationship spanning on multiple tables
Sorry Michael, there was a typo in my code, due to some wrong copy/paste or search/replace I guess, I'm afraid. The error I reported comes up mapping to `TransmLimit` and not `SurfaceRes` (which is the one already mapped above). I edited the pastebin: http://pastebin.com/mjfgPrcB now with: 'transm_limit': relationship(TransmLimit, single_parent=True, uselist=False, primaryjoin=and_( user_stratigraphies.c.id_prov==provinces.c.id, provinces.c.id_cz==transm_limits.c.id_cz, user_stratigraphies.c.id_str==stratigraphies.c.id, stratigraphies.c.id_tec==tech_elements_classes.c.id, tech_elements_classes.c.id_tu==transm_limits.c.id_tu, ), foreign_keys=( user_stratigraphies.c.id_prov, ), ), I get the error I reported: sqlalchemy.exc.ArgumentError: Could not locate any foreign-key-equated, locally mapped column pairs for primaryjoin condition 'user_stratigraphies.id_prov = provinces.id AND provinces.id_cz = transm_limits.id_cz AND user_stratigraphies.id_str = stratigraphies.id AND stratigraphies.id_tec = tech_elements_classes.id AND tech_elements_classes.id_tu = transm_limits.id_tu' on relationship ustratatigraphy.transm_limit. For more relaxed rules on join conditions, the relationship may be marked as viewonly=True. Also there's the strange `viewonly=True` behavior that breakes `UserStratigraphy.surface_res` relationship if uncommented. Thanks for your patience. neurino On Mon, Aug 1, 2011 at 11:14 PM, Michael Bayer mike...@zzzcomputing.comwrote: 'transm_limit': relationship(SurfaceRes, single_parent=True, #uselist=False, #primaryjoin=and_( #user_stratigraphies.c.id_prov==provinces.c.id, #provinces.c.id_cz==transm_limits.c.id_cz, #user_stratigraphies.c.id_str==stratigraphies.c.id, #stratigraphies.c.id_tec==tech_elements_classes.c.id, #tech_elements_classes.c.id_tu==transm_limits.c.id_tu, #), this fails because you aren't joining to the table to which SurfaceRes is mapped, surface_res. On Aug 1, 2011, at 7:02 AM, neurino wrote: I'm trying to get some relationships spanning on multiple tables (4 or 5). While I got the `4 tables` one working on first attempt (I was surpized I could...) I can't get the `5 tables` one to work while the code is almost the same. Moreover with the first relationship if I add adding `viewonly=True` initialization fails. I just need these to get (not even set) some values with convenience of SA attributes. I published a working example on pastebin: http://pastebin.com/RsZ6GCRq I hope someone can sort out this thing, thank you. Greetings neurino -- 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. -- 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. -- 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] Working with a ResultProxy object
In my controller class, I perform a rather basic, straightforward SQL
query:
connection = engine.connect()
trans = connection.begin()
try:
c.result = connection.execute(select
current_disposition_code,count(*) as num from cms_input_file group by
current_disposition_code;)
connection.close()
thus my c.result is an sqlalchemy.engine.base.ResultProxy object.
When I go to render this in a mako file as:
% for result in c.results:
${result.current_disposition_code}[${result.num}]
% endfor
I get no output. I am quite certain this is becuase I am using a
ResultProxy object. How can I output such an object inthe mako files,
or alternatively, how might i convert a ResultProxy objectsuch that I
can output it in a mako file? Thanks! RVince
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Re: [sqlalchemy] Working with a ResultProxy object
On Tue, Aug 2, 2011 at 3:07 PM, RVince rvinc...@gmail.com wrote:
In my controller class, I perform a rather basic, straightforward SQL
query:
connection = engine.connect()
trans = connection.begin()
try:
c.result = connection.execute(select
current_disposition_code,count(*) as num from cms_input_file group by
current_disposition_code;)
connection.close()
thus my c.result is an sqlalchemy.engine.base.ResultProxy object.
When I go to render this in a mako file as:
% for result in c.results:
${result.current_disposition_code}[${result.num}]
% endfor
I get no output. I am quite certain this is becuase I am using a
ResultProxy object. How can I output such an object inthe mako files,
or alternatively, how might i convert a ResultProxy objectsuch that I
can output it in a mako file? Thanks! RVince
Seems you missed fetching some rows from ResultProxy.
http://www.sqlalchemy.org/docs/core/connections.html#sqlalchemy.engine.base.ResultProxy
Hope this helps.
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[sqlalchemy] Re: Working with a ResultProxy object
Tamas,
I'm more confused now -- would I do this in my controller or in the
mako file? If, in my controller, dont I need to create an array for
each field, that is:
i = 0
for row in c.result
c.current_disposition_code[i] = row['current_disposition_code']
c.num[i] = row['num']
i = i + 1
I dont see how I can move, say, c.current_disposition_code and c.num
to the make output? I don't seem to be getting any output still (I'm
still missing something):
% for result in c.current_disposition_code:
${result}
% endfor
Thanks for your help and insight with this. RVince
On Aug 2, 9:26 am, Tamás Bajusz gbt...@gmail.com wrote:
On Tue, Aug 2, 2011 at 3:07 PM, RVince rvinc...@gmail.com wrote:
In my controller class, I perform a rather basic, straightforward SQL
query:
connection = engine.connect()
trans = connection.begin()
try:
c.result = connection.execute(select
current_disposition_code,count(*) as num from cms_input_file group by
current_disposition_code;)
connection.close()
thus my c.result is an sqlalchemy.engine.base.ResultProxy object.
When I go to render this in a mako file as:
% for result in c.results:
${result.current_disposition_code}[${result.num}]
% endfor
I get no output. I am quite certain this is becuase I am using a
ResultProxy object. How can I output such an object inthe mako files,
or alternatively, how might i convert a ResultProxy objectsuch that I
can output it in a mako file? Thanks! RVince
Seems you missed fetching some rows from
ResultProxy.http://www.sqlalchemy.org/docs/core/connections.html#sqlalchemy.engin...
Hope this helps.
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Re: [sqlalchemy] Updating user interface after rollback (using after_rollback SessionExtension?)
On Aug 2, 2011, at 3:33 AM, Torsten Landschoff wrote: I looked at the is_active flag in SQLAlchemy 0.6.8 already and I think I can only use it with autocommit disabled. Unfortunately I use autocommit=True. if you're in autocommit=True and you're calling session.flush() which fails, it rolls back just once, then the session is basically back to normal. You shouldn't be getting that error you're getting (unless you're doing your own nesting with begin()/rollback(), in which case is_active counts). Here's the full check for a Session that is usable: session.transaction is None or session.is_active with autocommit=True, session.transaction remains None when the Session is in between operations. -- 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.
Re: [sqlalchemy] Working with a ResultProxy object
On Aug 2, 2011, at 9:07 AM, RVince wrote: In my controller class, I perform a rather basic, straightforward SQL query: connection = engine.connect() connection, OK trans = connection.begin() start a transaction, OK try: c.result = connection.execute(select current_disposition_code,count(*) as num from cms_input_file group by current_disposition_code;) connection.close() close the connection ? what happened to trans, wheres the rollback or commit ? what about your c.result that hasn't been iterated yet ? both of these need an active Connection to proceed correctly. Technically the transaction is fine with just the connection.close() at the end but its a strange form that doesn't make the intent clear.The cursor referenced by the ResultProxy definitely should have exclusive access to its parent Connection for its whole lifespan, though, closing it out can have one of several negative effects, depending on the backend and the configuration of the connection pool. Want to know what would be easy here ? c.result = engine.execute(select * from my_table) then you're done. The ResultProxy in this case manages the Connection itself which will be closed when the ResultProxy closes. However this assumes you just need one SQL statement in a transaction, it seems that perhaps the begin() call is because you're doing several things with the one Connection. Ideally, assuming this is Pylons, you'd have a single Connection declared for all controllers up in your BaseController, with a trans = connection.begin() at the top and trans.rollback() at the bottom. That way the mechanics of providing database context to controllers is handled in application logic and not business logic.Or you'd have the ORM Session in place and just use Session.execute() to get a result. -- 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: Working with a ResultProxy object
Michael, Right, thats a better idea -- I am working with snippets of other people's code here. However, I still have the original problem of going from a ResultProxy object to output in a mako file which is a chasm I cannnot seem to bridge! RVInce On Aug 2, 10:06 am, Michael Bayer mike...@zzzcomputing.com wrote: On Aug 2, 2011, at 9:07 AM, RVince wrote: In my controller class, I perform a rather basic, straightforward SQL query: connection = engine.connect() connection, OK trans = connection.begin() start a transaction, OK try: c.result = connection.execute(select current_disposition_code,count(*) as num from cms_input_file group by current_disposition_code;) connection.close() close the connection ? what happened to trans, wheres the rollback or commit ? what about your c.result that hasn't been iterated yet ? both of these need an active Connection to proceed correctly. Technically the transaction is fine with just the connection.close() at the end but its a strange form that doesn't make the intent clear. The cursor referenced by the ResultProxy definitely should have exclusive access to its parent Connection for its whole lifespan, though, closing it out can have one of several negative effects, depending on the backend and the configuration of the connection pool. Want to know what would be easy here ? c.result = engine.execute(select * from my_table) then you're done. The ResultProxy in this case manages the Connection itself which will be closed when the ResultProxy closes. However this assumes you just need one SQL statement in a transaction, it seems that perhaps the begin() call is because you're doing several things with the one Connection. Ideally, assuming this is Pylons, you'd have a single Connection declared for all controllers up in your BaseController, with a trans = connection.begin() at the top and trans.rollback() at the bottom. That way the mechanics of providing database context to controllers is handled in application logic and not business logic. Or you'd have the ORM Session in place and just use Session.execute() to get a result. -- 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.
Re: [sqlalchemy] Re: Working with a ResultProxy object
On Aug 2, 2011, at 11:31 AM, RVince wrote: Michael, Right, thats a better idea -- I am working with snippets of other people's code here. However, I still have the original problem of going from a ResultProxy object to output in a mako file which is a chasm I cannnot seem to bridge! RVInce there's nothing wrong with assigning a ResultProxy to c.result, then iterating it in a template, as long as the connection context remains open. Your premature closing it is the likely issue here. On Aug 2, 10:06 am, Michael Bayer mike...@zzzcomputing.com wrote: On Aug 2, 2011, at 9:07 AM, RVince wrote: In my controller class, I perform a rather basic, straightforward SQL query: connection = engine.connect() connection, OK trans = connection.begin() start a transaction, OK try: c.result = connection.execute(select current_disposition_code,count(*) as num from cms_input_file group by current_disposition_code;) connection.close() close the connection ? what happened to trans, wheres the rollback or commit ? what about your c.result that hasn't been iterated yet ? both of these need an active Connection to proceed correctly. Technically the transaction is fine with just the connection.close() at the end but its a strange form that doesn't make the intent clear.The cursor referenced by the ResultProxy definitely should have exclusive access to its parent Connection for its whole lifespan, though, closing it out can have one of several negative effects, depending on the backend and the configuration of the connection pool. Want to know what would be easy here ? c.result = engine.execute(select * from my_table) then you're done. The ResultProxy in this case manages the Connection itself which will be closed when the ResultProxy closes. However this assumes you just need one SQL statement in a transaction, it seems that perhaps the begin() call is because you're doing several things with the one Connection. Ideally, assuming this is Pylons, you'd have a single Connection declared for all controllers up in your BaseController, with a trans = connection.begin() at the top and trans.rollback() at the bottom. That way the mechanics of providing database context to controllers is handled in application logic and not business logic.Or you'd have the ORM Session in place and just use Session.execute() to get a result. -- 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. -- 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: Working with a ResultProxy object
Michael,
But if I do the following, and do NOT close it (at least, I dont
believe I am now):
result = engine.execute(select
current_disposition_code,count(*) as num from cms_input_file group by
current_disposition_code;)
c.curent_disposition_codes = []
c.num = []
for row in result:
c.curent_disposition_codes.append(str(row['current_disposition_code']))
c.num.append(str(row['num'] ))
And I look in at c.curent_disposition_codes and c.num, and I see 4
values for each, then, when I go to render it with:
%
i = 0
%
% for result in c.current_disposition_codes:
${result}[${c.num.index(i)}]
%
i = i + 1
%
% endfor
I get no output at all. The last bit of code, the mako file, is
executing, and properly, but it is not outputting values -- is there
something obvious that I am missing here? Thanks so much for your help
here. RVince
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Re: [sqlalchemy] SQLAlchemy 0.7.2 Released
Thank you for all the effort you put in. SQLAlchemy has been a proven tool for me and as it seems for many others. On Aug 1, 2011, at 02:17 , Michael Bayer wrote: SQLAlchemy version 0.7.2 is now available. A lot has been going on leading up to this release, and there was actually a bunch more I've wanted to do; but as we went about six weeks since the last release we've accumulated at least twenty five bug fixes, and it's time for them to go out.Work continues towards the next release. This release features a relatively big change to the mechanics of joined and subquery eager loading, which is that when invoked from a Query (as opposed to from a lazy load), the eager loader will traverse the graph of objects fully regardless of collections and attributes that are already loaded, populating any expired or not-yet-loaded attributes all the way down the hierarchy. Previously it tried to save time by not descending into already loaded subtrees. This is to better support the use case of using eager loading in order to fully populate a tree, such that it can be detached and sent to a cache in a fully loaded state. It is also behaviorally closer to the spirit of I asked for X, I should get X, i.e. if you say subqueryload(), you'll get your subquery no matter what. Other than that there were a *lot* of ORM fixes, most of which have been also applied to the 0.6 branch and will be in 0.6.9. Also some additional 0.6-0.7 regressions fixed, and some fixes to the new Mutable extension including one which was kind of a show stopper. Download SQLAlchemy 0.7.2 at: http://www.sqlalchemy.org/download.html Changelog follows. 0.7.2 = - orm - Feature enhancement: joined and subquery loading will now traverse already-present related objects and collections in search of unpopulated attributes throughout the scope of the eager load being defined, so that the eager loading that is specified via mappings or query options unconditionally takes place for the full depth, populating whatever is not already populated. Previously, this traversal would stop if a related object or collection were already present leading to inconsistent behavior (though would save on loads/cycles for an already-loaded graph). For a subqueryload, this means that the additional SELECT statements emitted by subqueryload will invoke unconditionally, no matter how much of the existing graph is already present (hence the controversy). The previous behavior of stopping is still in effect when a query is the result of an attribute-initiated lazyload, as otherwise an N+1 style of collection iteration can become needlessly expensive when the same related object is encountered repeatedly. There's also an as-yet-not-public generative Query method _with_invoke_all_eagers() which selects old/new behavior [ticket:2213] - A rework of replacement traversal within the ORM as it alters selectables to be against aliases of things (i.e. clause adaption) includes a fix for multiply-nested any()/has() constructs against a joined table structure. [ticket:2195] - Fixed bug where query.join() + aliased=True from a joined-inh structure to itself on relationship() with join condition on the child table would convert the lead entity into the joined one inappropriately. [ticket:2234] Also in 0.6.9. - Fixed regression from 0.6 where Session.add() against an object which contained None in a collection would raise an internal exception. Reverted this to 0.6's behavior which is to accept the None but obviously nothing is persisted. Ideally, collections with None present or on append() should at least emit a warning, which is being considered for 0.8. [ticket:2205] - Load of a deferred() attribute on an object where row can't be located raises ObjectDeletedError instead of failing later on; improved the message in ObjectDeletedError to include other conditions besides a simple delete. [ticket:2191] - Fixed regression from 0.6 where a get history operation on some relationship() based attributes would fail when a lazyload would emit; this could trigger within a flush() under certain conditions. [ticket:2224] Thanks to the user who submitted the great test for this. - Fixed bug apparent only in Python 3 whereby sorting of persistent + pending objects during flush would produce an illegal comparison, if the persistent object primary key is not a single integer. [ticket:2228] Also in 0.6.9 - Fixed bug whereby the source clause used by query.join() would be inconsistent if against a column expression that combined multiple entities together. [ticket:2197] Also in 0.6.9 - Fixed bug whereby if a mapped class redefined __hash__() or
Re: [sqlalchemy] Re: Working with a ResultProxy object
On Aug 2, 2011, at 12:09 PM, RVince wrote:
Michael,
But if I do the following, and do NOT close it (at least, I dont
believe I am now):
result = engine.execute(select
current_disposition_code,count(*) as num from cms_input_file group by
current_disposition_code;)
c.curent_disposition_codes = []
c.num = []
for row in result:
c.curent_disposition_codes.append(str(row['current_disposition_code']))
c.num.append(str(row['num'] ))
And I look in at c.curent_disposition_codes and c.num, and I see 4
values for each, then, when I go to render it with:
%
i = 0
%
% for result in c.current_disposition_codes:
${result}[${c.num.index(i)}]
%
i = i + 1
%
% endfor
In this case you are running through the result proxy in your controller,
assigning to a collection, and its done. That is perfectly fine. Feel free
to close out the connection after iterating the result set.
Then, it is unusual that you're indexing what is basically a string, i.e. each
value of result with the [] operator though.
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Re: [sqlalchemy] SQLAlchemy 0.7.2 Released
I'd just like to echo Martin's statement, thank you very much. Just your responses to this list seem like a full time job, let alone the development to SQLAlchemy - which continues to surprise and impress me with it's features and support. James. On 08/02/2011 09:28 AM, Martijn Moeling wrote: Thank you for all the effort you put in. SQLAlchemy has been a proven tool for me and as it seems for many others. On Aug 1, 2011, at 02:17 , Michael Bayer wrote: SQLAlchemy version 0.7.2 is now available. A lot has been going on leading up to this release, and there was actually a bunch more I've wanted to do; but as we went about six weeks since the last release we've accumulated at least twenty five bug fixes, and it's time for them to go out.Work continues towards the next release. This release features a relatively big change to the mechanics of joined and subquery eager loading, which is that when invoked from a Query (as opposed to from a lazy load), the eager loader will traverse the graph of objects fully regardless of collections and attributes that are already loaded, populating any expired or not-yet-loaded attributes all the way down the hierarchy. Previously it tried to save time by not descending into already loaded subtrees. This is to better support the use case of using eager loading in order to fully populate a tree, such that it can be detached and sent to a cache in a fully loaded state. It is also behaviorally closer to the spirit of I asked for X, I should get X, i.e. if you say subqueryload(), you'll get your subquery no matter what. Other than that there were a *lot* of ORM fixes, most of which have been also applied to the 0.6 branch and will be in 0.6.9. Also some additional 0.6-0.7 regressions fixed, and some fixes to the new Mutable extension including one which was kind of a show stopper. Download SQLAlchemy 0.7.2 at: http://www.sqlalchemy.org/download.html Changelog follows. 0.7.2 = - orm - Feature enhancement: joined and subquery loading will now traverse already-present related objects and collections in search of unpopulated attributes throughout the scope of the eager load being defined, so that the eager loading that is specified via mappings or query options unconditionally takes place for the full depth, populating whatever is not already populated. Previously, this traversal would stop if a related object or collection were already present leading to inconsistent behavior (though would save on loads/cycles for an already-loaded graph). For a subqueryload, this means that the additional SELECT statements emitted by subqueryload will invoke unconditionally, no matter how much of the existing graph is already present (hence the controversy). The previous behavior of stopping is still in effect when a query is the result of an attribute-initiated lazyload, as otherwise an N+1 style of collection iteration can become needlessly expensive when the same related object is encountered repeatedly. There's also an as-yet-not-public generative Query method _with_invoke_all_eagers() which selects old/new behavior [ticket:2213] - A rework of replacement traversal within the ORM as it alters selectables to be against aliases of things (i.e. clause adaption) includes a fix for multiply-nested any()/has() constructs against a joined table structure. [ticket:2195] - Fixed bug where query.join() + aliased=True from a joined-inh structure to itself on relationship() with join condition on the child table would convert the lead entity into the joined one inappropriately. [ticket:2234] Also in 0.6.9. - Fixed regression from 0.6 where Session.add() against an object which contained None in a collection would raise an internal exception. Reverted this to 0.6's behavior which is to accept the None but obviously nothing is persisted. Ideally, collections with None present or on append() should at least emit a warning, which is being considered for 0.8. [ticket:2205] - Load of a deferred() attribute on an object where row can't be located raises ObjectDeletedError instead of failing later on; improved the message in ObjectDeletedError to include other conditions besides a simple delete. [ticket:2191] - Fixed regression from 0.6 where a get history operation on some relationship() based attributes would fail when a lazyload would emit; this could trigger within a flush() under certain conditions. [ticket:2224] Thanks to the user who submitted the great test for this. - Fixed bug apparent only in Python 3 whereby sorting of persistent + pending objects during flush would produce an illegal comparison, if the persistent object primary key is not a single integer. [ticket:2228] Also in 0.6.9 - Fixed bug
[sqlalchemy] Re: Working with a ResultProxy object
LOL,I'm going backwards here, and taking far too long to get something so very simple done (there's a genuine lack of documentation here I think -- the only way to manage to learn much of this is by trial and error). Rather than trying to do this with straight SQL statements I will go plan B here and try to rewrite their SQL library to be consistent with the SQL alchemy idiom for selecting. This way, I will get the output into these mako files. -- 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.
Re: [sqlalchemy] Integrity error when using association_proxy - one of the foreign keys is missing
Thanks so much for the help. For the record, setting an __init__ argument on
the association argument did the trick.
Ben
On 2 Aug 2011, at 01:47, Michael Bayer mike...@zzzcomputing.com wrote:
On Aug 1, 2011, at 8:34 PM, somewhatofftheway wrote:
Hi,
I'm trying to convert a 'simple' many-to-many relationship to an
association object in order to allow the relationship to have
attributes. I've followed the code in examples/association/
proxied_association.py fairly closely (or so I thought) but it isn't
working for me.
As an example, let's say I am trying to create a relationship between
an RSS feed and the pages from the feed but I want a feed_date on the
relationship. Currently, my code look something like this:
class Page (Base):
__tablename__ = 'pages'
id = Column(Integer, primary_key=True)
posts = relationship(Post, cascade=all, delete-orphan,
backref='pages')
feeds = association_proxy(feeds, feed)
class Post(Base)
__tablename__ = 'pages_feeds'
page_id = Column(Integer, ForeignKey('pages.id'),
primary_key=True)
feed_id = Column(Integer, ForeignKey('feeds.id'),
primary_key=True)
feed = relationship(Feed, lazy='joined')
I haven't changed the Feed class at all.
When I do something along the lines of:
page = Page()
feed = Feed()
page.feeds.append(feed)
the query that is issued is as follows:
IntegrityError: (IntegrityError) pages_feeds.feed_id may not be NULL
u'INSERT INTO pages_feeds (page_id) VALUES (?)' (1,)
So, clearly I have missed out the part of the config that explains
that adds in the second foreign key. Could anybody point me to where
please?
you need a constructor and/or creator that generates Post() with the feed
attached to it, like def __init__(self, feed): self.feed = feed, then the
assoc proxy with creator=Post.
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Re: [sqlalchemy] Re: Building hierarchy tree in reverse
Yes I'm using PostgreSQL and now that you've linked to the docs, I remember there was a possibility for recursion. Thanks for suggestion, I'll look into it. .oO V Oo. On 08/02/2011 03:41 AM, Gunnlaugur Briem wrote: You could look for recursive CTE (Common Table Expressions), if your database engine supports such queries. See e.g. http://www.postgresql.org/docs/8.4/static/queries-with.html for PostgreSQL. That allows arbitrary-depth queries, as opposed to join chains that have to assume a fixed depth. You could probably apply two recursive queries, one downward and one upward from the given node, to avoid querying the whole tree. SQLAlchemy has no support for CTEs directly, though of course you can construct the query manually and execute and fetch results through SQLAlchemy. You *can* get some support for recursive queries under SQLAlchemy in https://github.com/marplatense/sqla_hierarchy/ but be warned, that project is ... youthful :) Regards, - Gulli -- You received this message because you are subscribed to the Google Groups sqlalchemy group. To view this discussion on the web visit https://groups.google.com/d/msg/sqlalchemy/-/g7-7S4mBC3wJ. 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. -- 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] SA Unicode and SQLite
I'm trying to follow the instructions in the SA docs regarding Unicode and SQLite. I've declared all my character fields as either Unicode or UnicodeText. When populating the data, I specify strings as unicode strings (u'string'), but I'm still getting an warning: SAWarning Unicode type received non-unicode bind parameter, when I initially populate the database. On the next line, it reports param.append(processors[key](compiled_params[key])). Is this supposed to be telling me what the errant bind parameter is? I've turned on echo and looking at the queries and parameters, all the character parameters are specified as unicode strings, except for the dates which are given like '2011-08-02'. Are the dates what's causing the non-unicode bind parameter warning? I'm using SQLAlchemy 0.7.1, with Python 2.7.2 Thanks, Mark -- 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.
Re: [sqlalchemy] SA Unicode and SQLite
On Aug 2, 2011, at 6:35 PM, Mark Erbaugh wrote: I'm trying to follow the instructions in the SA docs regarding Unicode and SQLite. I've declared all my character fields as either Unicode or UnicodeText. When populating the data, I specify strings as unicode strings (u'string'), but I'm still getting an warning: SAWarning Unicode type received non-unicode bind parameter, when I initially populate the database. On the next line, it reports param.append(processors[key](compiled_params[key])). Is this supposed to be telling me what the errant bind parameter is? I've turned on echo and looking at the queries and parameters, all the character parameters are specified as unicode strings, except for the dates which are given like '2011-08-02'. Are the dates what's causing the non-unicode bind parameter warning? I'm using SQLAlchemy 0.7.1, with Python 2.7.2 Set the warnings filter to error and send off a stack trace, that will show exactly where the offending statement is (its not impossible that its within SQLA too). import warnings warnings.simplefilter(error) http://docs.python.org/library/warnings.html -- 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] misleading docs on logging
Hi All,
Just me or does this:
http://www.sqlalchemy.org/docs/core/engines.html?highlight=logging#configuring-logging
...imply that to get pool logging you just need to do:
import logging
logging.getLogger('sqlalchemy.pool').setLevel(logging.DEBUG)
Whereas, in fact, you need to do:
import logging
logging.getLogger('sqlalchemy').setLevel(logging.INFO)
logging.getLogger('sqlalchemy.pool').setLevel(logging.DEBUG)
logging.getLogger('sqlalchemy.engine').setLevel(logging.WARNING)
logging.getLogger('sqlalchemy.mapper').setLevel(logging.WARNING)
...to get just the pool logging, and then, with 0.6 at least, you find
that things like checking connections in and out of the pool don't
appear to be logged.
Am I missing something here?
cheers,
Chris
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Re: [sqlalchemy] SA Unicode and SQLite
On Aug 2, 2011, at 6:50 PM, Michael Bayer wrote: On Aug 2, 2011, at 6:35 PM, Mark Erbaugh wrote: I'm trying to follow the instructions in the SA docs regarding Unicode and SQLite. I've declared all my character fields as either Unicode or UnicodeText. When populating the data, I specify strings as unicode strings (u'string'), but I'm still getting an warning: SAWarning Unicode type received non-unicode bind parameter, when I initially populate the database. On the next line, it reports param.append(processors[key](compiled_params[key])). Is this supposed to be telling me what the errant bind parameter is? I've turned on echo and looking at the queries and parameters, all the character parameters are specified as unicode strings, except for the dates which are given like '2011-08-02'. Are the dates what's causing the non-unicode bind parameter warning? I'm using SQLAlchemy 0.7.1, with Python 2.7.2 Set the warnings filter to error and send off a stack trace, that will show exactly where the offending statement is (its not impossible that its within SQLA too). import warnings warnings.simplefilter(error) http://docs.python.org/library/warnings.html Thanks, that did the trick. Mark -- 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.
Re: [sqlalchemy] misleading docs on logging
On Aug 2, 2011, at 7:13 PM, Chris Withers wrote:
Hi All,
Just me or does this:
http://www.sqlalchemy.org/docs/core/engines.html?highlight=logging#configuring-logging
...imply that to get pool logging you just need to do:
import logging
logging.getLogger('sqlalchemy.pool').setLevel(logging.DEBUG)
Whereas, in fact, you need to do:
import logging
logging.getLogger('sqlalchemy').setLevel(logging.INFO)
logging.getLogger('sqlalchemy.pool').setLevel(logging.DEBUG)
logging.getLogger('sqlalchemy.engine').setLevel(logging.WARNING)
logging.getLogger('sqlalchemy.mapper').setLevel(logging.WARNING)
...to get just the pool logging, and then, with 0.6 at least, you find that
things like checking connections in and out of the pool don't appear to be
logged.
Am I missing something here?
Not sure if you're missing anything but I certainly am. sqlalchemy.pool is
the only logger involved with pool logging and I'm having a hard time imagining
how you've arrived at your result !
Here is a demo:
from sqlalchemy import create_engine
import logging
logging.basicConfig()
logging.getLogger(sqlalchemy.pool).setLevel(logging.DEBUG)
e = create_engine('sqlite://')
c = e.connect()
c.close()
here is the output with 0.6:
classics-MacBook-Pro:sa06 classic$ python test.py
DEBUG:sqlalchemy.pool.SingletonThreadPool.0x...2570:Created new connection
sqlite3.Connection object at 0x2dfc58
DEBUG:sqlalchemy.pool.SingletonThreadPool.0x...2570:Connection
sqlite3.Connection object at 0x2dfc58 checked out from pool
DEBUG:sqlalchemy.pool.SingletonThreadPool.0x...2570:Connection
sqlite3.Connection object at 0x2dfc58 being returned to pool
cheers,
Chris
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