Re: [sqlalchemy] Handling detached instances
On 30 Sep 2014, at 23:18, tonthon tontho...@gmail.com wrote: I didn't knew merge was supposes to be used in such a case, it works like a charm. Following that tip, I've added this decorator : def cache_wrapper(func): ensure a model returned from a cached function is attached to the current session def cached_func_wrapper(*args, **kwargs): obj = func(*args, **kwargs) if object_session(obj) is None and has_identity(obj): obj = DBSESSION().merge(obj) return obj return cached_func_wrapper Keep in mind that merge can still hit your SQL database to refresh and attributes. If you know your cache is not stale you will want to use the load=False parameter for merge() to prevent that from happening. Wichert. -- 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/d/optout.
[sqlalchemy] UNION howto
Hi all, Could someone help me to define in sqlalchemy the following query: sql=SELECT count(*) FROM (SELECT cod_sticker AS bruciato FROM scadenziario UNION SELECT cod_sticker AS bruciato FROM sopralluogo UNION SELECT sticker_checklist AS bruciato FROM sopralluogo UNION SELECT protocollo AS bruciato FROM prestazione) AS foo WHERE bruciato='E1212'; thank for any help. j -- 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/d/optout.
[sqlalchemy] Re: UNION howto
I asked a similar question a few days ago; it's still on the front page of
the group. Mike replied to that and gave some details
Your query would be something like:
class A(Base):
__tablename__ = 'a'
id = Column(Integer, primary_key=True)
cod_sticker = Column(String)
sticker_checklist = Column(String)
protocollo = Column(String)
q1 = sess.query(A.cod_sticker.label('bruciato'))
q2 = sess.query(A.cod_sticker.label('bruciato'))
q3 = sess.query(A.sticker_checklist.label('bruciato'))
q4 = sess.query(A.protocollo.label('bruciato'))
as_union = union(q1, q2, q3, q4)
as_union_alias = as_union.alias('foo')
q = sess.query(as_union_alias).filter( as_union_alias.c.bruciato ==
'E1212').count()
--
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/d/optout.
[sqlalchemy] statement.compile and legacy is not null code
I'm just posting this to the group for search equity--
Until recently (2012, via this commit
https://bitbucket.org/zzzeek/sqlalchemy/issue/2544), the way recommended
several times in this group and stackoverflow to generate IS NOT NULL was
to use a column opreation:
sq = sess.query(A.id.label('id')).filter(A.id.op('IS NOT')(None))
However, that will cause a sqlalchemy.exc.CompileError when print/compiling
a statement with literal binds
# this will raise an error
print str(sq.statement.compile(dialect=postgresql.dialect(),
compile_kwargs={literal_binds: True}))
To get around that issue, these forms will all compile correctly:
# 0.7.9 and later
sq = sess.query(A.id.label('id')).filter(A.id != None)
# 0.7.8 and earlier
sq = sess.query(A.id.label('id')).filter(A.id.op('IS
NOT')(sqlalchemy.sql.expression.null()))
--
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/d/optout.
Re: [sqlalchemy] statement.compile and legacy is not null code
On Wed, Oct 1, 2014 at 6:51 PM, Jonathan Vanasco jvana...@gmail.com wrote:
# 0.7.9 and later
sq = sess.query(A.id.label('id')).filter(A.id != None)
I've used ~(id == None) since 0.3 quite successfully (though I've
eventually switched to != None since it's way more natural so not sure
if there's any place where it doesn't compile well)
--
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/d/optout.
Re: [sqlalchemy] statement.compile and legacy is not null code
you have either x != None or x != null() or x.isnot(None), or
x.isnot(null()))
a lot of choices!
On Oct 1, 2014, at 5:51 PM, Jonathan Vanasco jvana...@gmail.com wrote:
I'm just posting this to the group for search equity--
Until recently (2012, via this commit
https://bitbucket.org/zzzeek/sqlalchemy/issue/2544), the way recommended
several times in this group and stackoverflow to generate IS NOT NULL was
to use a column opreation:
sq = sess.query(A.id.label('id')).filter(A.id.op('IS NOT')(None))
However, that will cause a sqlalchemy.exc.CompileError when print/compiling a
statement with literal binds
# this will raise an error
print str(sq.statement.compile(dialect=postgresql.dialect(),
compile_kwargs={literal_binds: True}))
To get around that issue, these forms will all compile correctly:
# 0.7.9 and later
sq = sess.query(A.id.label('id')).filter(A.id != None)
# 0.7.8 and earlier
sq = sess.query(A.id.label('id')).filter(A.id.op('IS
NOT')(sqlalchemy.sql.expression.null()))
--
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/d/optout.
--
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/d/optout.
