[sqlalchemy] Re: Operational Error raised by except_
I guess since, I learn it now, EXCEPT is not supported by MySQL... I guess I'll have to change my query at all... On Feb 22, 12:57 pm, neurino neur...@gmail.com wrote: I have now problems with except_ in MySQL: the code that worked flawlessly in sqlite now causes an error, seems right after EXCEPT in query: ProgrammingError: (ProgrammingError) (1064, You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'SELECT sensors.id_cu AS sensors_id_cu, sensors.id_meas AS sensors_id_meas, senso' at line 3) 'SELECT anon_1.sensors_id_cu AS anon_1_sensors_id_cu, anon_1.sensors_id_meas AS anon_1_sensors_id_meas, anon_1.sensors_id_elab AS anon_1_sensors_id_elab, anon_1.sensors_name AS anon_1_sensors_name, anon_1.sensors_desc AS anon_1_sensors_desc \nFROM (SELECT sensors.id_cu AS sensors_id_cu, sensors.id_meas AS sensors_id_meas, sensors.id_elab AS sensors_id_elab, sensors.name AS sensors_name, sensors.`desc` AS sensors_desc \nFROM sensors EXCEPT SELECT sensors.id_cu AS sensors_id_cu, sensors.id_meas AS sensors_id_meas, sensors.id_elab AS sensors_id_elab, sensors.name AS sensors_name, sensors.`desc` AS sensors_desc \nFROM sensors, view_opts \nWHERE sensors.id_cu = view_opts.id_cu AND sensors.id_meas = view_opts.id_meas AND view_opts.id_view = %s AND view_opts.id IS NOT NULL ORDER BY sensors.id_cu, sensors.id_meas) AS anon_1 ORDER BY anon_1.sensors_id_cu, anon_1.sensors_id_meas' (1L,) I'm using: * sqlalchemy 0.6.6 * MySQLdb 1.2.3 * MySQL Ver 14.14 Distrib 5.1.41, Thanks for your support 2011/1/13 neurino neur...@gmail.com Thanks Michael, just for following readers I precise the ORDER BY clause causing the OperationalError is the one coming *before* the EXCEPT so I had to add .order_by(None) to the first query, now it looks like: Session.query(model.Sensor) \ .order_by(None) \ .except_( Session.query(model.Sensor) \ .filter(model.Sensor.id_cu==model.ViewOpt.id_cu) \ .filter(model.Sensor.id_meas==model.ViewOpt.id_meas) \ .filter(model.ViewOpt.id_view==1) ) and works perfectly, thanks again! Cheers neurino On Jan 12, 5:28 pm, Michael Bayer mike...@zzzcomputing.com wrote: On Jan 12, 2011, at 11:20 AM, neurino wrote: Well as I wrote ordering involves everything, also forms creation with formalchemy (make a select where all sensors are ordered that way etc) anyway I understand your point of view. quickest is a where sensor id not in (query), as a simple WHERE clause Problem comes when Sensor primary key is composite (id_cu + id_meas)... The good 'ol python comes in handy anyway: all = Session.query(model.Sensor).all() selected = Session.query(model.Sensor).filter( ... model.Sensor.id_cu==model.ViewOpt.id_cu).filter( ... model.Sensor.id_meas==model.ViewOpt.id_meas).filter( ... model.ViewOpt.id_view==1).all() diff = [sens for sens in all if sens not in selected] len(all), len(selected), len(diff) (154, 6, 148) We're talking of working on max total 200/300 sensors. The OR way did not filter anything (maybe I made somwthing wrong). Oh you know what, I completely forgot the best solution. It *is* documented on query.order_by() though which is an argument forchecking! pass None to query.order_by(). That disables all order_by's for that query. So go back to your except_() and use except_(q.order_by(None)). Greetings On Jan 12, 4:04 pm, Michael Bayer mike...@zzzcomputing.com wrote: On Jan 12, 2011, at 8:46 AM, neurino wrote: I need always the same order_by in all app and it could be subject of modification and / or integration in the near future so which better place than mapper to define it once instead of any time I do a query? It sounds like the ordering here is for the purposes of view logic so I'd have view logic that is factored down to receive Query objects that return Sensor rows, the view logic then applies the .order_by() to the Query. I.e. in a web app I use a Paginator object of some kind that does this, given a Query. This is probably a reason I don't like order_by to be within mapper(), it doesn't define persistence, rather a view. Anyway do you think there are alternate paths to get `all sensors but already choosen` which are order_by compatible? quickest is a where sensor id not in (query), as a simple WHERE clause, or use OR, query sensor where sensor.cu != cu OR sensor.meas != meas OR sensor.view != view. Except is not as widely used and I think its not even supported by all backends, even though it is a nice logical set operator, its got annoying quirks like this one. Thanks for your support On Jan 12, 2:38 pm, Michael Bayer mike...@zzzcomputing.com wrote: On Jan 12, 2011, at 7:28 AM, neurino wrote: I have this model: ``I organize
[sqlalchemy] Unable to select on Table subclass
I wrote a simple subclass of Table class MyTable(Table): def __init__(self, name, metadata, *args, **kwargs): super(MyTable, self).__init__(name, metadata, *args, **kwargs) def select(self, whereclause=None): return super(BitemporalTable, self).select(self.c.z 1) == select(t) where t is an object of MyTable is giving this error. What is the solution... Traceback (most recent call last): File t.py, line 16, in module select(t) File /prod/tools/infra/SQLAlchemy-0.5.5-py2.5.egg/sqlalchemy/sql/ expression.py, line 246, in select s = Select(columns, whereclause=whereclause, from_obj=from_obj, **kwargs) File /prod/tools/infra/SQLAlchemy-0.5.5-py2.5.egg/sqlalchemy/sql/ expression.py, line 3239, in __init__ [_literal_as_column(c) for c in columns] TypeError: 'MyTable' object is not iterable -- 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: Unable to select on Table subclass
def select(self, whereclause=None): return super(MyTable, self).select(self.c.z 1) You can ignore this method. This error comes with out this method also. -- 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] SqlAlchemy+cx_oracle decimal point problem with stddev
Hi everyone, in my script (python 2.6, Oracle10g, cx_oracle 5.0.4, sqlalchemy 0.6.5) I'm running the following simple query on one of my tables: table = Table(my_data_table, metadata, autoload=True) col = getattr(table.c, my_integer_col) res = select(func.stdev(col)).execute().fetchone() where my_integer_col obviously contains only int values. I get the following error: ... File C:\Python26\lib\site-packages\sqlalchemy\engine\base.py, line 2445, in _fetchone_impl return self.cursor.fetchone() File C:\Python26\lib\site-packages\sqlalchemy\dialects\oracle \cx_oracle.py, line 496, in maybe_decimal return int(value) ValueError: invalid literal for int() with base 10: '18,89258326656747167219869520430353668307' I think this is related with the usage of the comma decimal point in the results, but the error is raised by the cx_oracle module so I cannot handle it. is this a bug or am I missing something? 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.
Re: [sqlalchemy] Unable to select on Table subclass
Table is not meant for subclassing, so you would need to read the source code
to understand these issues. The issue below cannot be reproduced:
from sqlalchemy import *
class MyTable(Table):
def __init__(self, name, metadata, *args, **kwargs):
super(MyTable, self).__init__(name, metadata, *args, **kwargs)
def bar(self):
return hi
m = MetaData()
mt = MyTable('foo', m, Column('id', Integer))
print mt.bar()
0.7 output:
hi
0.6 output:
hi
0.5 output:
hi
On Feb 22, 2011, at 8:30 AM, bool wrote:
I wrote a simple subclass of Table
class MyTable(Table):
def __init__(self, name, metadata, *args, **kwargs):
super(MyTable, self).__init__(name, metadata, *args, **kwargs)
def select(self, whereclause=None):
return super(BitemporalTable, self).select(self.c.z 1)
==
select(t) where t is an object of MyTable is giving this error. What
is the solution...
Traceback (most recent call last):
File t.py, line 16, in module
select(t)
File /prod/tools/infra/SQLAlchemy-0.5.5-py2.5.egg/sqlalchemy/sql/
expression.py, line 246, in select
s = Select(columns, whereclause=whereclause, from_obj=from_obj,
**kwargs)
File /prod/tools/infra/SQLAlchemy-0.5.5-py2.5.egg/sqlalchemy/sql/
expression.py, line 3239, in __init__
[_literal_as_column(c) for c in columns]
TypeError: 'MyTable' object is not iterable
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Re: [sqlalchemy] SqlAlchemy+cx_oracle decimal point problem with stddev
Regarding the comma, set NLS_LANG to a locale that uses a decimal point, or use 0.6.6, this behavior is described in the third paragraph at http://www.sqlalchemy.org/docs/dialects/oracle.html#precision-numerics . On Feb 22, 2011, at 8:54 AM, Massi wrote: Hi everyone, in my script (python 2.6, Oracle10g, cx_oracle 5.0.4, sqlalchemy 0.6.5) I'm running the following simple query on one of my tables: table = Table(my_data_table, metadata, autoload=True) col = getattr(table.c, my_integer_col) res = select(func.stdev(col)).execute().fetchone() where my_integer_col obviously contains only int values. I get the following error: ... File C:\Python26\lib\site-packages\sqlalchemy\engine\base.py, line 2445, in _fetchone_impl return self.cursor.fetchone() File C:\Python26\lib\site-packages\sqlalchemy\dialects\oracle \cx_oracle.py, line 496, in maybe_decimal return int(value) ValueError: invalid literal for int() with base 10: '18,89258326656747167219869520430353668307' I think this is related with the usage of the comma decimal point in the results, but the error is raised by the cx_oracle module so I cannot handle it. is this a bug or am I missing something? 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. -- 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] Unable to select on Table subclass
On Feb 22, 2011, at 8:30 AM, bool wrote: select(t) where t is an object of MyTable is giving this error. What is the solution... also, I recommend upgrading to a modern release of SQLAlchemy. The above usage produces this error: sqlalchemy.exc.ArgumentError: columns argument to select() must be a Python list or other iterable that is, select([t]). See http://www.sqlalchemy.org/docs/core/tutorial.html#selecting . -- 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: Operational Error raised by except_
Something like this: stmt = Session.query(model.ViewOpt.id_cu, model.ViewOpt.id_meas) \ .filter(model.ViewOpt.id_view==1).subquery() query = Session.query(model.Sensor) \ .outerjoin((stmt, and_(model.Sensor.id_cu==stmt.c.id_cu, model.Sensor.id_meas==stmt.c.id_meas))) \ .filter(and_(stmt.c.id_cu==None, stmt.c.id_meas==None)) Cheers 2011/2/22 neurino neur...@gmail.com I guess since, I learn it now, EXCEPT is not supported by MySQL... I guess I'll have to change my query at all... On Feb 22, 12:57 pm, neurino neur...@gmail.com wrote: I have now problems with except_ in MySQL: the code that worked flawlessly in sqlite now causes an error, seems right after EXCEPT in query: ProgrammingError: (ProgrammingError) (1064, You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'SELECT sensors.id_cu AS sensors_id_cu, sensors.id_meas AS sensors_id_meas, senso' at line 3) 'SELECT anon_1.sensors_id_cu AS anon_1_sensors_id_cu, anon_1.sensors_id_meas AS anon_1_sensors_id_meas, anon_1.sensors_id_elab AS anon_1_sensors_id_elab, anon_1.sensors_name AS anon_1_sensors_name, anon_1.sensors_desc AS anon_1_sensors_desc \nFROM (SELECT sensors.id_cu AS sensors_id_cu, sensors.id_meas AS sensors_id_meas, sensors.id_elab AS sensors_id_elab, sensors.name AS sensors_name, sensors.`desc` AS sensors_desc \nFROM sensors EXCEPT SELECT sensors.id_cu AS sensors_id_cu, sensors.id_meas AS sensors_id_meas, sensors.id_elab AS sensors_id_elab, sensors.name AS sensors_name, sensors.`desc` AS sensors_desc \nFROM sensors, view_opts \nWHERE sensors.id_cu = view_opts.id_cu AND sensors.id_meas = view_opts.id_meas AND view_opts.id_view = %s AND view_opts.id IS NOT NULL ORDER BY sensors.id_cu, sensors.id_meas) AS anon_1 ORDER BY anon_1.sensors_id_cu, anon_1.sensors_id_meas' (1L,) I'm using: * sqlalchemy 0.6.6 * MySQLdb 1.2.3 * MySQL Ver 14.14 Distrib 5.1.41, Thanks for your support 2011/1/13 neurino neur...@gmail.com Thanks Michael, just for following readers I precise the ORDER BY clause causing the OperationalError is the one coming *before* the EXCEPT so I had to add .order_by(None) to the first query, now it looks like: Session.query(model.Sensor) \ .order_by(None) \ .except_( Session.query(model.Sensor) \ .filter(model.Sensor.id_cu==model.ViewOpt.id_cu) \ .filter(model.Sensor.id_meas==model.ViewOpt.id_meas) \ .filter(model.ViewOpt.id_view==1) ) and works perfectly, thanks again! Cheers neurino On Jan 12, 5:28 pm, Michael Bayer mike...@zzzcomputing.com wrote: On Jan 12, 2011, at 11:20 AM, neurino wrote: Well as I wrote ordering involves everything, also forms creation with formalchemy (make a select where all sensors are ordered that way etc) anyway I understand your point of view. quickest is a where sensor id not in (query), as a simple WHERE clause Problem comes when Sensor primary key is composite (id_cu + id_meas)... The good 'ol python comes in handy anyway: all = Session.query(model.Sensor).all() selected = Session.query(model.Sensor).filter( ... model.Sensor.id_cu==model.ViewOpt.id_cu).filter( ... model.Sensor.id_meas==model.ViewOpt.id_meas).filter( ... model.ViewOpt.id_view==1).all() diff = [sens for sens in all if sens not in selected] len(all), len(selected), len(diff) (154, 6, 148) We're talking of working on max total 200/300 sensors. The OR way did not filter anything (maybe I made somwthing wrong). Oh you know what, I completely forgot the best solution. It *is* documented on query.order_by() though which is an argument forchecking! pass None to query.order_by(). That disables all order_by's for that query. So go back to your except_() and use except_(q.order_by(None)). Greetings On Jan 12, 4:04 pm, Michael Bayer mike...@zzzcomputing.com wrote: On Jan 12, 2011, at 8:46 AM, neurino wrote: I need always the same order_by in all app and it could be subject of modification and / or integration in the near future so which better place than mapper to define it once instead of any time I do a query? It sounds like the ordering here is for the purposes of view logic so I'd have view logic that is factored down to receive Query objects that return Sensor rows, the view logic then applies the .order_by() to the Query. I.e. in a web app I use a Paginator object of some kind that does this, given a Query. This is probably a reason I don't like order_by to be within mapper(), it doesn't define persistence, rather a view. Anyway do you think there are alternate paths to get `all sensors but already choosen` which are
[sqlalchemy] Create Database trought sqlalchemy 0.6.6 !
Hi,
I would like to know how to create database with sqlalchemy using the
PostGresql driver, are there a sample or example?
sqlalchemy just only works with database postgresql previous created.
see my code:
import sqlalchemy
from sqlalchemy import create_engine, Table, MetaData, Integer,
String, ForeignKey, Column, LargeBinary
db_engine = create_engine('postgresql+psycopg2://
postgres:magi1850@localhost/newscom')
metadata = MetaData()
metadata.create_all(db_engine)
Error message:
sqlalchemy.exc.OperationalError: (OperationalError) FATAL: database
newscom2 does not exist
None None
Any ideas ?
Toninho Nunes
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[sqlalchemy] Re: adjacency via table
thought i'd post the code I came up with for reference:
from sqlalchemy import *
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import relationship, sessionmaker
from sqlalchemy.ext.associationproxy import association_proxy
Base = declarative_base()
def _create_inheritance(supertype, subtype):
return Inheritance(supertype, subtype)
inheritance_table = Table('inheritance', Base.metadata,
Column('sub_name', String(50), ForeignKey('types.name'),
primary_key=True),
Column('super_name', String(50), ForeignKey('types.name'),
primary_key=True))
class Type(Base):
__tablename__ = 'types'
name = Column(String(50), primary_key=True)
abstract = Column(Boolean)
top = Column(Boolean)
subtypes = relationship('Type',
secondary=inheritance_table,
primaryjoin=inheritance_table.c.super_name==name,
secondaryjoin=inheritance_table.c.sub_name==name,
backref='supertypes')
def hasSuper(self):
return self.supertypes.length 0
def hasSub(self):
return self.subtypes.length 0
def isAnySubOf(self, tp):
#to check for cyclic inheritance
if self == tp:
return True
for typ in self.supertypes:
if typ.isAnySubOf(tp):
return True
return False
def isAnySuperOf(self, tp):
return tp.isAnySubOf(self)
def addSub(self, tp):
#some types cannot have supertypes:
if not tp.top:
#to check for cyclic inheritance:
if not self.isAnySubOf(tp):
self.subtypes.append(tp)
else: raise Exception(cyclic inheritance)
else: raise Exception(str(tp) + cannot have supertype)
def addSuper(self, tp):
tp.addSub(self)
def __init__(self, name, top = False, abstract = False):
self.name = name
self.top = top
self.abstract = abstract
def __repr__(self):
return Type(%r) % (self.name)
engine = create_engine('sqlite:///:memory:', echo=False)
Base.metadata.create_all(engine)
if __name__ == __main__:
Session = sessionmaker(bind=engine)
session = Session()
try:
c1 = Type(A)
c2 = Type(B)
c3 = Type(C)
c1.addSub(c2)
c3.addSuper(c1)
c3.addSuper(c2)
c3.addSub(c1) #= would be cyclic
print c1.subs
for c in c1.subtypes:
print + str(c)
print c1.supers
for c in c1.supertypes:
print +str(c)
print c2.subs
for c in c2.subtypes:
print + str(c)
print c2.supers
for c in c2.supertypes:
print + str(c)
print c3.subs
for c in c3.subtypes:
print + str(c)
print c3.supers
for c in c3.supertypes:
print + str(c)
except Exception, e:
print error: + str(e)
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Re: [sqlalchemy] self-referential relationship w/ declarative style
On Feb 20, 2011, at 10:12 PM, Ryan wrote:
I'm attempting a self-referential mapping on a Client object that includes
these two columns:
id = Column(Integer, primary_key=True)
inviter_id = Column(Integer, ForeignKey('users.id'), nullable=True)
Started here with no luck:
inviter = relationship('Client', primaryjoin='Client.id ==
Client.inviter_id', uselist=False)
Then read about self-referential mapping in the docs and tried with no luck:
inviter = relationship('Client', remote_side='Client.id', uselist=False)
And this with an error:
relationship('Client', remote_side=[Client.id], uselist=False)
Would be a great help to see how this is done in a declarative style. Thanks!
the last example in the section
http://www.sqlalchemy.org/docs/orm/relationships.html#adjacency-list-relationships
illustrates a declarative self-referential relationship. Note that the id
Column object can be referenced directly when you're inside the class
declaration itself.
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Re: [sqlalchemy] Is it possible to have single transaction across several http calls?
Holding open a transaction across several web requests is in general a bad
idea. HTTP is stateless - the requests could be spaced hours apart or not at
all, leaving the transaction hanging open permanently. While the transaction
is open, locks may be held, preventing concurrent activities upon the affected
rows from proceeding.
That said, one simple way to do this would be to stow away the
transaction-holding object, assuming its a Session(), in some kind of storage
(most likely a dictionary) where it is accessed by each successive request.
The full series of requests would need to take place in a single process.
A more robust method, if you're on Postgresql or MySQL, would be to defer the
commit of several individual transactions using two phase xids. This would
enable a collection of per-connection transactions to participate in a larger
two phase operation. Each request emits the PREPARE command with a distinct
xid, storing the transaction's state on disk. Then COMMIT PREPARED is emitted
for each. Docs on this for Postgresql are at
http://www.postgresql.org/docs/current/static/sql-prepare-transaction.html .
The SQLAlchemy Connection object can provide a conversation like this as
follows:
from sqlalchemy import *
e = create_engine('postgresql://scott:tiger@localhost/test', echo=True)
e.execute(drop table if exists foo)
e.execute(create table foo(id integer))
c = e.connect()
t1 = c.begin_twophase()
c.execute(insert into foo (id) values (1))
t1.prepare()
c.close()
c = e.connect()
t2 = c.begin_twophase()
c.execute(insert into foo (id) values (2))
t2.prepare()
c.close()
c = e.connect()
t3 = c.begin_twophase()
c.execute(insert into foo (id) values (3))
t3.prepare()
c.close()
c = e.connect()
for t in (t1, t2, t3):
c.commit_prepared(t.xid, recover=True)
print e.execute(select * from foo).fetchall()
If using that with a Session, you'd need to embed the Session in the
transaction using a scheme similar to the one described at
http://www.sqlalchemy.org/docs/orm/session.html#joining-a-session-into-an-external-transaction
(just not within the context of a unit test).
On Feb 21, 2011, at 12:35 AM, Andrey Gladilin wrote:
I have a big RESTfull API in my python web application using Werkzeug
and SQLAlchemy. Could you advise some way to use a single transaction
across several http calls?
Thanks!
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Re: [sqlalchemy] commit() okay on every web request ?
calling commit() on every request is fine, as long as you aren't creating unwanted 'dirty' state inadvertently.Watching your SQL logs could help you to determine if things are happening that are undesirable. On Feb 21, 2011, at 3:38 AM, Romy wrote: Switched to autocommit=False, and calling commit(), followed by remove() on every end-of-request, regardless of whether there's data to commit or not. Am I adding any unnecessary overhead ? And if so, how should I be checking for dirtyness prior to committing ? R -- 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] Small docs problem
Just noticed that the 0.6.6 docs show a name parameter of subquery(), but it does not yet seem to be available in 0.6.6. There should be a note that it can only be used in 0.6.7 or 0.7. -- 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 sqlalchemy+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/sqlalchemy?hl=en.
[sqlalchemy] Re: Create Database trought sqlalchemy 0.6.6 !
sqlalchemy allows you to issue any literal sql statements as text:
http://www.sqlalchemy.org/docs/core/tutorial.html#using-text
On Feb 22, 7:38 am, Toninho Nunes toninhonu...@gmail.com wrote:
Hi,
I would like to know how to create database with sqlalchemy using the
PostGresql driver, are there a sample or example?
sqlalchemy just only works with database postgresql previous created.
see my code:
import sqlalchemy
from sqlalchemy import create_engine, Table, MetaData, Integer,
String, ForeignKey, Column, LargeBinary
db_engine = create_engine('postgresql+psycopg2://
postgres:magi1850@localhost/newscom')
metadata = MetaData()
metadata.create_all(db_engine)
Error message:
sqlalchemy.exc.OperationalError: (OperationalError) FATAL: database
newscom2 does not exist
None None
Any ideas ?
Toninho Nunes
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[sqlalchemy] Re: Create Database trought sqlalchemy 0.6.6 !
Even with that autocommit transaction isolation level, you probably
need to commit the create database before you try to add tables to
it.
On Feb 22, 1:45 pm, Toninho Nunes toninhonu...@gmail.com wrote:
Hi see my source code below
import sqlalchemy
import psycopg2
from sqlalchemy import create_engine, Table, MetaData, Integer,
String, ForeignKey, Column, LargeBinary
from sqlalchemy.sql import text
db_engine = create_engine('postgresql+psycopg2://
postgres:password@localhost/newscom3', echo=True)
db_engine.raw_connection().set_isolation_level(psycopg2.extensions.ISOLATION_LEVEL_AUTOCOMMIT)
db_engine.text(CREATE DATABASE newscom3 WITH OWNER = postgres
ENCODING = 'UTF8' TABLESPACE = pg_default LC_COLLATE = 'pt_BR.utf8'
LC_CTYPE = 'pt_BR.utf8' CONNECTION LIMIT = -1;).execute()
metadata = MetaData()
metadata.create_all(db_engine)
I run the source code, but I receive the following error.
Traceback (most recent call last):
File newscomddl.py, line 18, in module
db_engine.raw_connection().set_isolation_level(psycopg2.extensions.ISOLATION_LEVEL_AUTOCOMMIT)
File /usr/local/lib/python2.6/dist-packages/SQLAlchemy-0.6.6-
py2.6.egg/sqlalchemy/engine/base.py, line 1874, in raw_connection
return self.pool.unique_connection()
File /usr/local/lib/python2.6/dist-packages/SQLAlchemy-0.6.6-
py2.6.egg/sqlalchemy/pool.py, line 142, in unique_connection
return _ConnectionFairy(self).checkout()
File /usr/local/lib/python2.6/dist-packages/SQLAlchemy-0.6.6-
py2.6.egg/sqlalchemy/pool.py, line 369, in __init__
rec = self._connection_record = pool.get()
File /usr/local/lib/python2.6/dist-packages/SQLAlchemy-0.6.6-
py2.6.egg/sqlalchemy/pool.py, line 213, in get
return self.do_get()
File /usr/local/lib/python2.6/dist-packages/SQLAlchemy-0.6.6-
py2.6.egg/sqlalchemy/pool.py, line 732, in do_get
con = self.create_connection()
File /usr/local/lib/python2.6/dist-packages/SQLAlchemy-0.6.6-
py2.6.egg/sqlalchemy/pool.py, line 147, in create_connection
return _ConnectionRecord(self)
File /usr/local/lib/python2.6/dist-packages/SQLAlchemy-0.6.6-
py2.6.egg/sqlalchemy/pool.py, line 253, in __init__
self.connection = self.__connect()
File /usr/local/lib/python2.6/dist-packages/SQLAlchemy-0.6.6-
py2.6.egg/sqlalchemy/pool.py, line 319, in __connect
connection = self.__pool._creator()
File /usr/local/lib/python2.6/dist-packages/SQLAlchemy-0.6.6-
py2.6.egg/sqlalchemy/engine/strategies.py, line 82, in connect
return dialect.connect(*cargs, **cparams)
File /usr/local/lib/python2.6/dist-packages/SQLAlchemy-0.6.6-
py2.6.egg/sqlalchemy/engine/default.py, line 249, in connect
return self.dbapi.connect(*cargs, **cparams)
sqlalchemy.exc.OperationalError: (OperationalError) FATAL: database
newscom3 does not exist
None None
I don't get know where are wrong, could you help me?
Thanks,
Toninho Nunes
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Re: [sqlalchemy] PostgreSQL BIT type not properly supported by dialect
this has been fixed in 0.7, however it is completely a mystery how the change got in there, and it doesn't have test coverage. I'm thinking perhaps someone on IRC handed me a patch or something and I forgot it was there since it was committed along with something not really related: http://www.sqlalchemy.org/trac/changeset/7154#file5 so that's your patch, if you want to provide tests we can also backport to 0.6. The actual change is a two liner. On Feb 22, 2011, at 8:54 PM, Rami Chowdhury wrote: Hi, We're using PostgreSQL's BIT type to store bit-strings (http://www.postgresql.org/docs/current/static/datatype-bit.html), and (at least as of SQLA 0.6.6) the PostgreSQL dialect's BIT type doesn't seem to support those kinds of fields -- it just issues BIT when creating the tables, and we get 1-bit fields! At the moment (for table creation at least) we're getting around this using the following: class PG_BIT(sqlalchemy.dialects.postgresql.BIT): def __init__(self, length=None, *args, **kw): # Takes one positional arg, the bit length. Can be omitted self._bit_length = length @sqlalchemy.ext.compiler.compiles(PG_BIT) def compile_PG_BIT(element, compiler, **kw): if element._bit_length: return BIT(%d) % element._bit_length else: return compiler.visit_BIT(element, **kw) and using PG_BIT everywhere we'd want to use BIT. Obviously, though, it'd be great if SQLAlchemy supported this better. I'm very happy to try and work up a patch myself, but I'd appreciate advice on : - what I should try to patch (postgresql.BIT and postgresql.base.PGTypeCompiler are my first guesses) - what kind of coding / testing practices I should observe - should I try and write a patch against hg tip? against the 0.6.6 release? - is there anything I'm missing? Thanks! Rami -- Rami Chowdhury Never assume malice when stupidity will suffice. -- Hanlon's Razor +44-7581-430-517 / +1-408-597-7068 / +88-0189-245544 -- 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.
Re: [sqlalchemy] self-referential relationship w/ declarative style
On Feb 22, 2011, at 9:03 PM, Ryan McKillen wrote:
Mike, thanks a lot. Big help. I'm almost there.
This seems to do the trick:
usersid = Column(Integer, primary_key=True, key='id')
inviter_id = Column(Integer, ForeignKey('users.id'))
inviter = relationship('User',
uselist = False,
backref = backref('invitee', remote_side=usersid, uselist=True),
)
When there are two users, one being the inviter (parent) and the other being
the invitee (child), it works like a charm:
self.assertEqual(invitee1.inviter.id, inviter.id)
self.assertEqual(inviter.invitee[0].id, invitee1.id)
But add a third user, one being the inviter and two being the invitees,
invitee1.inviter is None.
probably because of that uselist=False, which makes it into a one-to-one.
Adjacency list is a standard single foreign key relationship - one-to-many on
one side, many-to-one on the other.
There's an illustration of exactly how the data resides in the table:
http://www.sqlalchemy.org/docs/orm/relationships.html#adjacency-list-relationships
Any ideas for me?
On Tue, Feb 22, 2011 at 7:54 AM, Michael Bayer mike...@zzzcomputing.com
wrote:
On Feb 20, 2011, at 10:12 PM, Ryan wrote:
I'm attempting a self-referential mapping on a Client object that includes
these two columns:
id = Column(Integer, primary_key=True)
inviter_id = Column(Integer, ForeignKey('users.id'), nullable=True)
Started here with no luck:
inviter = relationship('Client', primaryjoin='Client.id ==
Client.inviter_id', uselist=False)
Then read about self-referential mapping in the docs and tried with no luck:
inviter = relationship('Client', remote_side='Client.id', uselist=False)
And this with an error:
relationship('Client', remote_side=[Client.id], uselist=False)
Would be a great help to see how this is done in a declarative style.
Thanks!
the last example in the section
http://www.sqlalchemy.org/docs/orm/relationships.html#adjacency-list-relationships
illustrates a declarative self-referential relationship. Note that the id
Column object can be referenced directly when you're inside the class
declaration itself.
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Re: [sqlalchemy] Re: Create Database trought sqlalchemy 0.6.6 !
Setting an autocommit setting on a single raw_connection() won't work also
because that's just one connection out of several in the pool. The operation
should be performed on a Connection:
c = engine.connect()
c.detach() # so it is never returned to the pool, since we're changing settings
c.connection.set_isolation_level(...)
c.execute(statement)
Will add this in 0.7 to psycopg2's allowed list of isolation modes:
c.execution_options(isolation_level='AUTOCOMMIT') - ticket #2072
On Feb 22, 2011, at 9:18 PM, Eric Ongerth wrote:
Even with that autocommit transaction isolation level, you probably
need to commit the create database before you try to add tables to
it.
On Feb 22, 1:45 pm, Toninho Nunes toninhonu...@gmail.com wrote:
Hi see my source code below
import sqlalchemy
import psycopg2
from sqlalchemy import create_engine, Table, MetaData, Integer,
String, ForeignKey, Column, LargeBinary
from sqlalchemy.sql import text
db_engine = create_engine('postgresql+psycopg2://
postgres:password@localhost/newscom3', echo=True)
db_engine.raw_connection().set_isolation_level(psycopg2.extensions.ISOLATION_LEVEL_AUTOCOMMIT)
db_engine.text(CREATE DATABASE newscom3 WITH OWNER = postgres
ENCODING = 'UTF8' TABLESPACE = pg_default LC_COLLATE = 'pt_BR.utf8'
LC_CTYPE = 'pt_BR.utf8' CONNECTION LIMIT = -1;).execute()
metadata = MetaData()
metadata.create_all(db_engine)
I run the source code, but I receive the following error.
Traceback (most recent call last):
File newscomddl.py, line 18, in module
db_engine.raw_connection().set_isolation_level(psycopg2.extensions.ISOLATION_LEVEL_AUTOCOMMIT)
File /usr/local/lib/python2.6/dist-packages/SQLAlchemy-0.6.6-
py2.6.egg/sqlalchemy/engine/base.py, line 1874, in raw_connection
return self.pool.unique_connection()
File /usr/local/lib/python2.6/dist-packages/SQLAlchemy-0.6.6-
py2.6.egg/sqlalchemy/pool.py, line 142, in unique_connection
return _ConnectionFairy(self).checkout()
File /usr/local/lib/python2.6/dist-packages/SQLAlchemy-0.6.6-
py2.6.egg/sqlalchemy/pool.py, line 369, in __init__
rec = self._connection_record = pool.get()
File /usr/local/lib/python2.6/dist-packages/SQLAlchemy-0.6.6-
py2.6.egg/sqlalchemy/pool.py, line 213, in get
return self.do_get()
File /usr/local/lib/python2.6/dist-packages/SQLAlchemy-0.6.6-
py2.6.egg/sqlalchemy/pool.py, line 732, in do_get
con = self.create_connection()
File /usr/local/lib/python2.6/dist-packages/SQLAlchemy-0.6.6-
py2.6.egg/sqlalchemy/pool.py, line 147, in create_connection
return _ConnectionRecord(self)
File /usr/local/lib/python2.6/dist-packages/SQLAlchemy-0.6.6-
py2.6.egg/sqlalchemy/pool.py, line 253, in __init__
self.connection = self.__connect()
File /usr/local/lib/python2.6/dist-packages/SQLAlchemy-0.6.6-
py2.6.egg/sqlalchemy/pool.py, line 319, in __connect
connection = self.__pool._creator()
File /usr/local/lib/python2.6/dist-packages/SQLAlchemy-0.6.6-
py2.6.egg/sqlalchemy/engine/strategies.py, line 82, in connect
return dialect.connect(*cargs, **cparams)
File /usr/local/lib/python2.6/dist-packages/SQLAlchemy-0.6.6-
py2.6.egg/sqlalchemy/engine/default.py, line 249, in connect
return self.dbapi.connect(*cargs, **cparams)
sqlalchemy.exc.OperationalError: (OperationalError) FATAL: database
newscom3 does not exist
None None
I don't get know where are wrong, could you help me?
Thanks,
Toninho Nunes
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Re: [sqlalchemy] self-referential relationship w/ declarative style
I added that in because without it I get:
TypeError: Incompatible collection type: User is not list-like
On Tue, Feb 22, 2011 at 6:47 PM, Michael Bayer mike...@zzzcomputing.comwrote:
On Feb 22, 2011, at 9:03 PM, Ryan McKillen wrote:
Mike, thanks a lot. Big help. I'm almost there.
This seems to do the trick:
usersid = Column(Integer, primary_key=True, key='id')
inviter_id = Column(Integer, ForeignKey('users.id'))
inviter = relationship('User',
uselist = False,
backref = backref('invitee', remote_side=usersid, uselist=True),
)
When there are two users, one being the inviter (parent) and the other
being the invitee (child), it works like a charm:
self.assertEqual(invitee1.inviter.id, inviter.id)
self.assertEqual(inviter.invitee[0].id, invitee1.id)
But add a third user, one being the inviter and two being the invitees,
invitee1.inviter is None.
probably because of that uselist=False, which makes it into a one-to-one.
Adjacency list is a standard single foreign key relationship - one-to-many
on one side, many-to-one on the other.
There's an illustration of exactly how the data resides in the table:
http://www.sqlalchemy.org/docs/orm/relationships.html#adjacency-list-relationships
Any ideas for me?
On Tue, Feb 22, 2011 at 7:54 AM, Michael Bayer
mike...@zzzcomputing.comwrote:
On Feb 20, 2011, at 10:12 PM, Ryan wrote:
I'm attempting a self-referential mapping on a Client object that includes
these two columns:
id = Column(Integer, primary_key=True)
inviter_id = Column(Integer, ForeignKey('users.id'), nullable=True)
Started here with no luck:
inviter = relationship('Client', primaryjoin='Client.id ==
Client.inviter_id', uselist=False)
Then read about self-referential mapping in the docs and tried with no
luck:
inviter = relationship('Client', remote_side='Client.id', uselist=False)
And this with an error:
relationship('Client', remote_side=[Client.id], uselist=False)
Would be a great help to see how this is done in a declarative style.
Thanks!
the last example in the section
http://www.sqlalchemy.org/docs/orm/relationships.html#adjacency-list-relationshipsillustrates
a declarative self-referential relationship. Note that the id
Column object can be referenced directly when you're inside the class
declaration itself.
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Re: [sqlalchemy] self-referential relationship w/ declarative style
one side scalar, one side collection. the collection side you use .append().
You decide which end is the non-collection by setting remote_side, in your
code below its invitee.
On Feb 22, 2011, at 9:59 PM, Ryan McKillen wrote:
I added that in because without it I get:
TypeError: Incompatible collection type: User is not list-like
On Tue, Feb 22, 2011 at 6:47 PM, Michael Bayer mike...@zzzcomputing.com
wrote:
On Feb 22, 2011, at 9:03 PM, Ryan McKillen wrote:
Mike, thanks a lot. Big help. I'm almost there.
This seems to do the trick:
usersid = Column(Integer, primary_key=True, key='id')
inviter_id = Column(Integer, ForeignKey('users.id'))
inviter = relationship('User',
uselist = False,
backref = backref('invitee', remote_side=usersid, uselist=True),
)
When there are two users, one being the inviter (parent) and the other being
the invitee (child), it works like a charm:
self.assertEqual(invitee1.inviter.id, inviter.id)
self.assertEqual(inviter.invitee[0].id, invitee1.id)
But add a third user, one being the inviter and two being the invitees,
invitee1.inviter is None.
probably because of that uselist=False, which makes it into a one-to-one.
Adjacency list is a standard single foreign key relationship - one-to-many on
one side, many-to-one on the other.
There's an illustration of exactly how the data resides in the table:
http://www.sqlalchemy.org/docs/orm/relationships.html#adjacency-list-relationships
Any ideas for me?
On Tue, Feb 22, 2011 at 7:54 AM, Michael Bayer mike...@zzzcomputing.com
wrote:
On Feb 20, 2011, at 10:12 PM, Ryan wrote:
I'm attempting a self-referential mapping on a Client object that includes
these two columns:
id = Column(Integer, primary_key=True)
inviter_id = Column(Integer, ForeignKey('users.id'), nullable=True)
Started here with no luck:
inviter = relationship('Client', primaryjoin='Client.id ==
Client.inviter_id', uselist=False)
Then read about self-referential mapping in the docs and tried with no luck:
inviter = relationship('Client', remote_side='Client.id', uselist=False)
And this with an error:
relationship('Client', remote_side=[Client.id], uselist=False)
Would be a great help to see how this is done in a declarative style.
Thanks!
the last example in the section
http://www.sqlalchemy.org/docs/orm/relationships.html#adjacency-list-relationships
illustrates a declarative self-referential relationship. Note that the
id Column object can be referenced directly when you're inside the class
declaration itself.
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Re: [sqlalchemy] self-referential relationship w/ declarative style
Got it. Many thanks!
On Tue, Feb 22, 2011 at 7:02 PM, Michael Bayer mike...@zzzcomputing.comwrote:
one side scalar, one side collection. the collection side you use
.append(). You decide which end is the non-collection by setting
remote_side, in your code below its invitee.
On Feb 22, 2011, at 9:59 PM, Ryan McKillen wrote:
I added that in because without it I get:
TypeError: Incompatible collection type: User is not list-like
On Tue, Feb 22, 2011 at 6:47 PM, Michael Bayer
mike...@zzzcomputing.comwrote:
On Feb 22, 2011, at 9:03 PM, Ryan McKillen wrote:
Mike, thanks a lot. Big help. I'm almost there.
This seems to do the trick:
usersid = Column(Integer, primary_key=True, key='id')
inviter_id = Column(Integer, ForeignKey('users.id'))
inviter = relationship('User',
uselist = False,
backref = backref('invitee', remote_side=usersid, uselist=True),
)
When there are two users, one being the inviter (parent) and the other
being the invitee (child), it works like a charm:
self.assertEqual(invitee1.inviter.id, inviter.id)
self.assertEqual(inviter.invitee[0].id, invitee1.id)
But add a third user, one being the inviter and two being the invitees,
invitee1.inviter is None.
probably because of that uselist=False, which makes it into a one-to-one.
Adjacency list is a standard single foreign key relationship -
one-to-many on one side, many-to-one on the other.
There's an illustration of exactly how the data resides in the table:
http://www.sqlalchemy.org/docs/orm/relationships.html#adjacency-list-relationships
Any ideas for me?
On Tue, Feb 22, 2011 at 7:54 AM, Michael Bayer
mike...@zzzcomputing.comwrote:
On Feb 20, 2011, at 10:12 PM, Ryan wrote:
I'm attempting a self-referential mapping on a Client object that
includes these two columns:
id = Column(Integer, primary_key=True)
inviter_id = Column(Integer, ForeignKey('users.id'), nullable=True)
Started here with no luck:
inviter = relationship('Client', primaryjoin='Client.id ==
Client.inviter_id', uselist=False)
Then read about self-referential mapping in the docs and tried with no
luck:
inviter = relationship('Client', remote_side='Client.id', uselist=False)
And this with an error:
relationship('Client', remote_side=[Client.id], uselist=False)
Would be a great help to see how this is done in a declarative style.
Thanks!
the last example in the section
http://www.sqlalchemy.org/docs/orm/relationships.html#adjacency-list-relationshipsillustrates
a declarative self-referential relationship. Note that the id
Column object can be referenced directly when you're inside the class
declaration itself.
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[sqlalchemy] Re: Create Database trought sqlalchemy 0.6.6 !
You are right, but I would like to create the database without to
connect to
other database existent, I'm newbie learning python and sqlalchemy.
any example will be welcome.
Thanks a lot
On Feb 22, 6:06 pm, Warwick Prince warwi...@mushroomsys.com wrote:
Hi Toninho
Looks to me that the issue is that your original create_engine is connecting
to the DB /newscom3, which you have not yet created. (i.e. you are just
about to create it, but it does not exist YET).
I'm not sure exactly (so forgive me if I'm wrong) but I would assume you
would possibly need to connect to another DB and then create newcom3 and
then create a new engine connected to the newly created DB..
Worth a try anyway! :-)
Cheers
Warwick
On 23 February 2011 07:45, Toninho Nunes toninhonu...@gmail.com wrote:
Hi see my source code below
import sqlalchemy
import psycopg2
from sqlalchemy import create_engine, Table, MetaData, Integer,
String, ForeignKey, Column, LargeBinary
from sqlalchemy.sql import text
db_engine = create_engine('postgresql+psycopg2://
postgres:password@localhost/newscom3', echo=True)
db_engine.raw_connection().set_isolation_level(psycopg2.extensions.ISOLATIO
N_LEVEL_AUTOCOMMIT)
db_engine.text(CREATE DATABASE newscom3 WITH OWNER = postgres
ENCODING = 'UTF8' TABLESPACE = pg_default LC_COLLATE = 'pt_BR.utf8'
LC_CTYPE = 'pt_BR.utf8' CONNECTION LIMIT = -1;).execute()
metadata = MetaData()
metadata.create_all(db_engine)
I run the source code, but I receive the following error.
Traceback (most recent call last):
File newscomddl.py, line 18, in module
db_engine.raw_connection().set_isolation_level(psycopg2.extensions.ISOLATIO
N_LEVEL_AUTOCOMMIT)
File /usr/local/lib/python2.6/dist-packages/SQLAlchemy-0.6.6-
py2.6.egg/sqlalchemy/engine/base.py, line 1874, in raw_connection
return self.pool.unique_connection()
File /usr/local/lib/python2.6/dist-packages/SQLAlchemy-0.6.6-
py2.6.egg/sqlalchemy/pool.py, line 142, in unique_connection
return _ConnectionFairy(self).checkout()
File /usr/local/lib/python2.6/dist-packages/SQLAlchemy-0.6.6-
py2.6.egg/sqlalchemy/pool.py, line 369, in __init__
rec = self._connection_record = pool.get()
File /usr/local/lib/python2.6/dist-packages/SQLAlchemy-0.6.6-
py2.6.egg/sqlalchemy/pool.py, line 213, in get
return self.do_get()
File /usr/local/lib/python2.6/dist-packages/SQLAlchemy-0.6.6-
py2.6.egg/sqlalchemy/pool.py, line 732, in do_get
con = self.create_connection()
File /usr/local/lib/python2.6/dist-packages/SQLAlchemy-0.6.6-
py2.6.egg/sqlalchemy/pool.py, line 147, in create_connection
return _ConnectionRecord(self)
File /usr/local/lib/python2.6/dist-packages/SQLAlchemy-0.6.6-
py2.6.egg/sqlalchemy/pool.py, line 253, in __init__
self.connection = self.__connect()
File /usr/local/lib/python2.6/dist-packages/SQLAlchemy-0.6.6-
py2.6.egg/sqlalchemy/pool.py, line 319, in __connect
connection = self.__pool._creator()
File /usr/local/lib/python2.6/dist-packages/SQLAlchemy-0.6.6-
py2.6.egg/sqlalchemy/engine/strategies.py, line 82, in connect
return dialect.connect(*cargs, **cparams)
File /usr/local/lib/python2.6/dist-packages/SQLAlchemy-0.6.6-
py2.6.egg/sqlalchemy/engine/default.py, line 249, in connect
return self.dbapi.connect(*cargs, **cparams)
sqlalchemy.exc.OperationalError: (OperationalError) FATAL: database
newscom3 does not exist
None None
I don't get know where are wrong, could you help me?
Thanks,
Toninho Nunes
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