Re: sqlite3 puzzle
On 15 January 2013 07:09, llanitedave llanited...@veawb.coop wrote:
So I put the following test code in my initialization method:
# open database file
self.geologger_db = sqlite3.connect('geologger.mgc')
self.db_cursor = self.geologger_db.cursor()
self.foreign_key_status = self.db_cursor.execute(PRAGMA foreign_keys =
ON)
self.foreign_key_status = self.foreign_key_status.fetchone()
print self.foreign_key_status
I ran this several times while I was arranging the downstream queries, and
each time it returned '(1,)', which means foreign keys is enabled.
But I was using a variable named 'cmd1' as a placeholder until I changed the
name to
the more descriptive 'self.foreign_key_status'. Since I made the name
change, however,
the code only returns 'None'. Reverting to the previous variable name has no
effect.
Hmm - your code doesn't quite match up with the docs at
http://docs.python.org/2/library/sqlite3.html. That seems to suggest
that you should call fetchone() on the cursor, not on the result of
execute().
Does the following work?
# open database file
self.geologger_db = sqlite3.connect('geologger.mgc')
self.db_cursor = self.geologger_db.cursor()
self.db_cursor.execute(PRAGMA foreign_keys = ON)
print self.db_cursor.fetchone()
--
Robert K. Day
robert@merton.oxon.org
--
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Re: sqlite3 puzzle
On Tuesday, January 15, 2013 6:36:51 AM UTC-8, Rob Day wrote:
On 15 January 2013 07:09, llanitedave llanited...@veawb.coop wrote:
So I put the following test code in my initialization method:
# open database file
self.geologger_db = sqlite3.connect('geologger.mgc')
self.db_cursor = self.geologger_db.cursor()
self.foreign_key_status = self.db_cursor.execute(PRAGMA foreign_keys =
ON)
self.foreign_key_status = self.foreign_key_status.fetchone()
print self.foreign_key_status
I ran this several times while I was arranging the downstream queries, and
each time it returned '(1,)', which means foreign keys is enabled.
But I was using a variable named 'cmd1' as a placeholder until I changed
the name to
the more descriptive 'self.foreign_key_status'. Since I made the name
change, however,
the code only returns 'None'. Reverting to the previous variable name has
no effect.
Hmm - your code doesn't quite match up with the docs at
http://docs.python.org/2/library/sqlite3.html. That seems to suggest
that you should call fetchone() on the cursor, not on the result of
execute().
Does the following work?
# open database file
self.geologger_db = sqlite3.connect('geologger.mgc')
self.db_cursor = self.geologger_db.cursor()
self.db_cursor.execute(PRAGMA foreign_keys = ON)
print self.db_cursor.fetchone()
--
Robert K. Day
robert@merton.oxon.org
Thanks for the suggestion, Rob, but that didn't make any difference. I've
never had an issue with putting the execute object into a variable and calling
fetch on that variable.
I can accept reality if it turns out that foreign keys simply isn't enabled on
the Python distribution of sqlite, although I don't know why that should be the
case. I'm just curious as to why it worked at first and then stopped working.
--
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Re: sqlite3 puzzle
On 15 January 2013 15:51, llanitedave llanited...@veawb.coop wrote:
Thanks for the suggestion, Rob, but that didn't make any difference. I've
never had an issue with putting the execute object into a variable and
calling fetch on that variable.
I can accept reality if it turns out that foreign keys simply isn't enabled
on the Python distribution of sqlite, although I don't know why that should
be the case. I'm just curious as to why it worked at first and then stopped
working.
Well - you might be able to accept that, but I'm not sure I can! If it
was working before, it must be compiled in, and so it must be possible
to make it work again.
http://www.sqlite.org/foreignkeys.html#fk_enable seems to suggest that
PRAGMA foreign_keys = ON never returns anything, and it's only
PRAGMA foreign_keys which returns 0, 1 or None (when unsupported).
With that in mind, does the following code work?
# open database file
self.geologger_db = sqlite3.connect('geologger.mgc')
self.db_cursor = self.geologger_db.cursor()
self.db_cursor.execute(PRAGMA foreign_keys = ON)
self.db_cursor.execute(PRAGMA foreign_keys)
print self.db_cursor.fetchone()
--
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Re: sqlite3 puzzle
On Monday, January 14, 2013 11:09:28 PM llanitedave wrote:
I'm trying to get an application working in Python 2.7 and wx.Python which
contains an embedded sqlite3 file. There are a few tables with foreign
keys defined. In looking at the sqlite3 documentation, it says
Assuming the library is compiled with foreign key constraints enabled, it
must still be enabled by the application at runtime, using the PRAGMA
foreign_keys command. It goes on to say that foreign keys must be enabled
separately for each connection, which is fine as my app has only one.
So I put the following test code in my initialization method:
# open database file
self.geologger_db = sqlite3.connect('geologger.mgc')
self.db_cursor = self.geologger_db.cursor()
self.foreign_key_status = self.db_cursor.execute(PRAGMA foreign_keys =
ON) self.foreign_key_status = self.foreign_key_status.fetchone()
print self.foreign_key_status
I ran this several times while I was arranging the downstream queries, and
each time it returned '(1,)', which means foreign keys is enabled.
But I was using a variable named 'cmd1' as a placeholder until I changed the
name to the more descriptive 'self.foreign_key_status'. Since I made the
name change, however, the code only returns 'None'. Reverting to the
previous variable name has no effect.
Yes, I'm closing the connection with self.db_cursor.close() at the end of
each run.
According to the sqlite3 website, getting no return value, not even a '0',
means that the version of SQLite you are using does not support foreign
keys (either because it is older than 3.6.19 or because it was compiled
with SQLITE_OMIT_FOREIGN_KEY or SQLITE_OMIT_TRIGGER defined).
How can that be a compilation issue when it worked previously? Does this
somehow relate to it being a Python plugin instance?
I'm very confused.
I haven't run this myself but after
self.foreign_key_status.fetchone()
try :
self.geologger_db.commit()
then close the db
jimonlinux
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Re: sqlite3 puzzle
On Tuesday, January 15, 2013 9:13:13 AM UTC-8, Rob Day wrote:
On 15 January 2013 15:51, llanitedave llanited...@veawb.coop wrote:
Thanks for the suggestion, Rob, but that didn't make any difference. I've
never had an issue with putting the execute object into a variable and
calling fetch on that variable.
I can accept reality if it turns out that foreign keys simply isn't enabled
on the Python distribution of sqlite, although I don't know why that should
be the case. I'm just curious as to why it worked at first and then
stopped working.
Well - you might be able to accept that, but I'm not sure I can! If it
was working before, it must be compiled in, and so it must be possible
to make it work again.
http://www.sqlite.org/foreignkeys.html#fk_enable seems to suggest that
PRAGMA foreign_keys = ON never returns anything, and it's only
PRAGMA foreign_keys which returns 0, 1 or None (when unsupported).
With that in mind, does the following code work?
# open database file
self.geologger_db = sqlite3.connect('geologger.mgc')
self.db_cursor = self.geologger_db.cursor()
self.db_cursor.execute(PRAGMA foreign_keys = ON)
self.db_cursor.execute(PRAGMA foreign_keys)
print self.db_cursor.fetchone()
http://www.sqlite.org/foreignkeys.html#fk_enable seems to suggest that PRAGMA
foreign_keys = ON never returns anything, and it's only PRAGMA foreign_keys
which returns 0, 1 or None (when unsupported).
That was it, exactly, Rob. I don't know where I got the idea that I was
getting a '1' from the 'ON' command, although I was sure that I'd seen it.
But once I just called foreign_key it returned just fine.
Ummm... Obviously I was up fiddling around too late. Yeah, that's it.
Thanks! It's solved now.
--
http://mail.python.org/mailman/listinfo/python-list
Re: sqlite3 puzzle
Glad I could help!
evangelism
Using a local source control system like git, bzr or hg is really
useful in situations like these - it's far, far easier to debug issues
of the form I made changes and now it's broken when you can do `git
diff yesterday's-version today's-version` and see exactly what the
changes were.
/evangelism
On 15 January 2013 20:29, llanitedave llanited...@veawb.coop wrote:
On Tuesday, January 15, 2013 9:13:13 AM UTC-8, Rob Day wrote:
On 15 January 2013 15:51, llanitedave llanited...@veawb.coop wrote:
Thanks for the suggestion, Rob, but that didn't make any difference. I've
never had an issue with putting the execute object into a variable and
calling fetch on that variable.
I can accept reality if it turns out that foreign keys simply isn't
enabled on the Python distribution of sqlite, although I don't know why
that should be the case. I'm just curious as to why it worked at first
and then stopped working.
Well - you might be able to accept that, but I'm not sure I can! If it
was working before, it must be compiled in, and so it must be possible
to make it work again.
http://www.sqlite.org/foreignkeys.html#fk_enable seems to suggest that
PRAGMA foreign_keys = ON never returns anything, and it's only
PRAGMA foreign_keys which returns 0, 1 or None (when unsupported).
With that in mind, does the following code work?
# open database file
self.geologger_db = sqlite3.connect('geologger.mgc')
self.db_cursor = self.geologger_db.cursor()
self.db_cursor.execute(PRAGMA foreign_keys = ON)
self.db_cursor.execute(PRAGMA foreign_keys)
print self.db_cursor.fetchone()
http://www.sqlite.org/foreignkeys.html#fk_enable seems to suggest that
PRAGMA foreign_keys = ON never returns anything, and it's only PRAGMA
foreign_keys which returns 0, 1 or None (when unsupported).
That was it, exactly, Rob. I don't know where I got the idea that I was
getting a '1' from the 'ON' command, although I was sure that I'd seen it.
But once I just called foreign_key it returned just fine.
Ummm... Obviously I was up fiddling around too late. Yeah, that's it.
Thanks! It's solved now.
--
http://mail.python.org/mailman/listinfo/python-list
--
Robert K. Day
robert@merton.oxon.org
--
http://mail.python.org/mailman/listinfo/python-list
Re: sqlite3 puzzle
Yabut I'm talking about changes I'd made 30 seconds before to code I'd written
5 minutes before. My short-term memory is nothing to write home about, even if
I could remember my mailing address!
On Tuesday, January 15, 2013 2:27:28 PM UTC-8, Rob Day wrote:
Glad I could help!
evangelism
Using a local source control system like git, bzr or hg is really
useful in situations like these - it's far, far easier to debug issues
of the form I made changes and now it's broken when you can do `git
diff yesterday's-version today's-version` and see exactly what the
changes were.
/evangelism
On 15 January 2013 20:29, llanitedave llanited...@veawb.coop wrote:
On Tuesday, January 15, 2013 9:13:13 AM UTC-8, Rob Day wrote:
On 15 January 2013 15:51, llanitedave llanited...@veawb.coop wrote:
Thanks for the suggestion, Rob, but that didn't make any difference.
I've never had an issue with putting the execute object into a variable
and calling fetch on that variable.
I can accept reality if it turns out that foreign keys simply isn't
enabled on the Python distribution of sqlite, although I don't know why
that should be the case. I'm just curious as to why it worked at first
and then stopped working.
Well - you might be able to accept that, but I'm not sure I can! If it
was working before, it must be compiled in, and so it must be possible
to make it work again.
http://www.sqlite.org/foreignkeys.html#fk_enable seems to suggest that
PRAGMA foreign_keys = ON never returns anything, and it's only
PRAGMA foreign_keys which returns 0, 1 or None (when unsupported).
With that in mind, does the following code work?
# open database file
self.geologger_db = sqlite3.connect('geologger.mgc')
self.db_cursor = self.geologger_db.cursor()
self.db_cursor.execute(PRAGMA foreign_keys = ON)
self.db_cursor.execute(PRAGMA foreign_keys)
print self.db_cursor.fetchone()
http://www.sqlite.org/foreignkeys.html#fk_enable seems to suggest that
PRAGMA foreign_keys = ON never returns anything, and it's only PRAGMA
foreign_keys which returns 0, 1 or None (when unsupported).
That was it, exactly, Rob. I don't know where I got the idea that I was
getting a '1' from the 'ON' command, although I was sure that I'd seen it.
But once I just called foreign_key it returned just fine.
Ummm... Obviously I was up fiddling around too late. Yeah, that's it.
Thanks! It's solved now.
--
http://mail.python.org/mailman/listinfo/python-list
--
Robert K. Day
robert@merton.oxon.org
--
http://mail.python.org/mailman/listinfo/python-list
sqlite3 puzzle
I'm trying to get an application working in Python 2.7 and wx.Python which
contains an embedded sqlite3 file. There are a few tables with foreign keys
defined. In looking at the sqlite3 documentation, it says
Assuming the library is compiled with foreign key constraints enabled, it must
still be enabled by the application at runtime, using the PRAGMA foreign_keys
command.
It goes on to say that foreign keys must be enabled separately for each
connection, which is fine as my app has only one.
So I put the following test code in my initialization method:
# open database file
self.geologger_db = sqlite3.connect('geologger.mgc')
self.db_cursor = self.geologger_db.cursor()
self.foreign_key_status = self.db_cursor.execute(PRAGMA foreign_keys = ON)
self.foreign_key_status = self.foreign_key_status.fetchone()
print self.foreign_key_status
I ran this several times while I was arranging the downstream queries, and each
time it returned '(1,)', which means foreign keys is enabled.
But I was using a variable named 'cmd1' as a placeholder until I changed the
name to the more descriptive 'self.foreign_key_status'. Since I made the name
change, however, the code only returns 'None'. Reverting to the previous
variable name has no effect.
Yes, I'm closing the connection with self.db_cursor.close() at the end of each
run.
According to the sqlite3 website, getting no return value, not even a '0',
means that the version of SQLite you are using does not support foreign keys
(either because it is older than 3.6.19 or because it was compiled with
SQLITE_OMIT_FOREIGN_KEY or SQLITE_OMIT_TRIGGER defined).
How can that be a compilation issue when it worked previously? Does this
somehow relate to it being a Python plugin instance?
I'm very confused.
--
http://mail.python.org/mailman/listinfo/python-list
