[google-appengine] Re: why there is no way to build a key id?
Just star'd it -thx.
2009/6/24 Jeff S (Google) j...@google.com:
Hi Jeff,
This is an idea that we're aware of as well. If you could reserve the next
ID in advance, then you could actually do this in one put since multiple
entities could be sent in one batch :-) The workaround available now is to
use the key_name, but the difficulty becomes ensuring that the key_name is
unique. Here is a feature request which I'm aware of which is along these
lines (though the approach differs slightly):
http://code.google.com/p/googleappengine/issues/detail?id=1003
Thank you,
Jeff
2009/6/24 Jeff Enderwick jeff.enderw...@gmail.com
Hey Jeff - sorry for the confusion. The idea was that one would be
able to get the unique id from an GOOG and then do a db.put with that
id as an arg. For example, let's say I want to create two entities,
with each referring to each other. I need to do three db.put
operations:
a = Foo()
db.put(a)
b = Foo()
b.ref = a.key()
db.put(b)
a.ref = b.key()
db.put(a)
One would hope to be able to do this with two db.puts.
Thanks,
Jeff
2009/6/16 Jeff S (Google) j...@google.com:
The datastore does not allow key_names which begin with a digit in
order to avoid confusion with an ID, which is numerical. If you want
to use numeric key names, you could add a one letter prefix :-)
Happy coding,
Jeff
On Jun 16, 1:17 am, cryb cbuti...@gmail.com wrote:
Hi Jeff.
Thanks for your reply.. I really hope that in the near future
appengine will support setting key ids for entities.
You mentioned that I can use hooks in order to achieve my goal..
However I was more interested in a solution based on appengine java
sdk, and not on python hooks. Does appengine java sdk provide hooks or
some other similar mechanism?
It seems that for the moment I'll stick to generating key names.
One more question: I've tried to generate some entities with key names
on my local devappserver and I got a strange exception stating that I
can't create key names that start with a digit (?!?)... this holds on
google appengine production servers too or it's just a bug of
devappserver?
Thanks
On Jun 16, 2:45 am, Jeff S (Google) j...@google.com wrote:
Hi cryb,
As you noted, we do not currently allow the ID for a key to be set,
as we
ensure that the ID is unique for each existing entity. I recommend
using a
key name instead of an ID, as Antoniov suggeted, if possible.
It is technically possible to modify the key of an entity as it is
being
converted to a protocol buffer message before it is sent to the
datastore.
You could do this using hooks in the API proxy as described in this
article:http://code.google.com/appengine/articles/hooks.htmlAlsoit is
possible to
construct the key for the desired object if you know the ID in
advance.
class X(db.Model):
pass
# If you've already created the entity so you have the ID.
x_id = X().put().id()
# Instead of getting by ID, you can create the key manually.
k = db.Key.from_path('X', x_id)
Now you have the desired key without having fetched the object, but
the part
which the model class does not allow is setting the key yourself. So
you
could modify the protocol buffer message before it is written to the
datastore, but I don't recommend it.
The decision to allow setting key_names but not IDs is something we
may
revisit.
Happy coding,
Jeff
2009/6/12 cryb cbuti...@gmail.com
Hi.. that is to build key names... What I asked was why I can't
build
a key ID..
On Jun 12, 5:35 am, Antoniov nio@gmail.com wrote:
Use the code:
s = Story(key_name=xzy123)
Then you create an entity with the key name xzy123.
Check this:
http://code.google.com/intl/en-US/appengine/docs/python/datastore/key...
On 6月12日, 上午1时28分, cryb cbuti...@gmail.com wrote:
Does anyone know why it is possible to build a key name but NOT
a key
id? I know key IDs are used as autoincrements, but why can't I
just
override this mechanism and build my own key id?
Suppose I want to overwrite an existent entry in my table that
has a
key id I know, and also I want to keep that key id after
update...
because I can't just build a key id, I am forced to fetch that
entity,
modify it and write it back, instead of just write the updated
entity
with the key id I already know - so an additional read to the
datastore.
Is there an obscure reason for that? (both key names and key
ids are
prefixed with appid/kind as far as I know so there is no chance
of
collision with other apps/kinds)
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You received this message because you are subscribed to the Google Groups
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[google-appengine] Re: why there is no way to build a key id?
Hey Jeff - sorry for the confusion. The idea was that one would be
able to get the unique id from an GOOG and then do a db.put with that
id as an arg. For example, let's say I want to create two entities,
with each referring to each other. I need to do three db.put
operations:
a = Foo()
db.put(a)
b = Foo()
b.ref = a.key()
db.put(b)
a.ref = b.key()
db.put(a)
One would hope to be able to do this with two db.puts.
Thanks,
Jeff
2009/6/16 Jeff S (Google) j...@google.com:
The datastore does not allow key_names which begin with a digit in
order to avoid confusion with an ID, which is numerical. If you want
to use numeric key names, you could add a one letter prefix :-)
Happy coding,
Jeff
On Jun 16, 1:17 am, cryb cbuti...@gmail.com wrote:
Hi Jeff.
Thanks for your reply.. I really hope that in the near future
appengine will support setting key ids for entities.
You mentioned that I can use hooks in order to achieve my goal..
However I was more interested in a solution based on appengine java
sdk, and not on python hooks. Does appengine java sdk provide hooks or
some other similar mechanism?
It seems that for the moment I'll stick to generating key names.
One more question: I've tried to generate some entities with key names
on my local devappserver and I got a strange exception stating that I
can't create key names that start with a digit (?!?)... this holds on
google appengine production servers too or it's just a bug of
devappserver?
Thanks
On Jun 16, 2:45 am, Jeff S (Google) j...@google.com wrote:
Hi cryb,
As you noted, we do not currently allow the ID for a key to be set, as we
ensure that the ID is unique for each existing entity. I recommend using a
key name instead of an ID, as Antoniov suggeted, if possible.
It is technically possible to modify the key of an entity as it is being
converted to a protocol buffer message before it is sent to the datastore.
You could do this using hooks in the API proxy as described in this
article:http://code.google.com/appengine/articles/hooks.htmlAlsoit is
possible to
construct the key for the desired object if you know the ID in advance.
class X(db.Model):
pass
# If you've already created the entity so you have the ID.
x_id = X().put().id()
# Instead of getting by ID, you can create the key manually.
k = db.Key.from_path('X', x_id)
Now you have the desired key without having fetched the object, but the
part
which the model class does not allow is setting the key yourself. So you
could modify the protocol buffer message before it is written to the
datastore, but I don't recommend it.
The decision to allow setting key_names but not IDs is something we may
revisit.
Happy coding,
Jeff
2009/6/12 cryb cbuti...@gmail.com
Hi.. that is to build key names... What I asked was why I can't build
a key ID..
On Jun 12, 5:35 am, Antoniov nio@gmail.com wrote:
Use the code:
s = Story(key_name=xzy123)
Then you create an entity with the key name xzy123.
Check this:
http://code.google.com/intl/en-US/appengine/docs/python/datastore/key...
On 6月12日, 上午1时28分, cryb cbuti...@gmail.com wrote:
Does anyone know why it is possible to build a key name but NOT a key
id? I know key IDs are used as autoincrements, but why can't I just
override this mechanism and build my own key id?
Suppose I want to overwrite an existent entry in my table that has a
key id I know, and also I want to keep that key id after update...
because I can't just build a key id, I am forced to fetch that
entity,
modify it and write it back, instead of just write the updated entity
with the key id I already know - so an additional read to the
datastore.
Is there an obscure reason for that? (both key names and key ids are
prefixed with appid/kind as far as I know so there is no chance of
collision with other apps/kinds)
--~--~-~--~~~---~--~~
You received this message because you are subscribed to the Google Groups
Google App Engine group.
To post to this group, send email to google-appengine@googlegroups.com
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[google-appengine] Re: why there is no way to build a key id?
Hi Jeff,
This is an idea that we're aware of as well. If you could reserve the next
ID in advance, then you could actually do this in one put since multiple
entities could be sent in one batch :-) The workaround available now is to
use the key_name, but the difficulty becomes ensuring that the key_name is
unique. Here is a feature request which I'm aware of which is along these
lines (though the approach differs slightly):
http://code.google.com/p/googleappengine/issues/detail?id=1003
Thank you,
Jeff
2009/6/24 Jeff Enderwick jeff.enderw...@gmail.com
Hey Jeff - sorry for the confusion. The idea was that one would be
able to get the unique id from an GOOG and then do a db.put with that
id as an arg. For example, let's say I want to create two entities,
with each referring to each other. I need to do three db.put
operations:
a = Foo()
db.put(a)
b = Foo()
b.ref = a.key()
db.put(b)
a.ref = b.key()
db.put(a)
One would hope to be able to do this with two db.puts.
Thanks,
Jeff
2009/6/16 Jeff S (Google) j...@google.com:
The datastore does not allow key_names which begin with a digit in
order to avoid confusion with an ID, which is numerical. If you want
to use numeric key names, you could add a one letter prefix :-)
Happy coding,
Jeff
On Jun 16, 1:17 am, cryb cbuti...@gmail.com wrote:
Hi Jeff.
Thanks for your reply.. I really hope that in the near future
appengine will support setting key ids for entities.
You mentioned that I can use hooks in order to achieve my goal..
However I was more interested in a solution based on appengine java
sdk, and not on python hooks. Does appengine java sdk provide hooks or
some other similar mechanism?
It seems that for the moment I'll stick to generating key names.
One more question: I've tried to generate some entities with key names
on my local devappserver and I got a strange exception stating that I
can't create key names that start with a digit (?!?)... this holds on
google appengine production servers too or it's just a bug of
devappserver?
Thanks
On Jun 16, 2:45 am, Jeff S (Google) j...@google.com wrote:
Hi cryb,
As you noted, we do not currently allow the ID for a key to be set, as
we
ensure that the ID is unique for each existing entity. I recommend
using a
key name instead of an ID, as Antoniov suggeted, if possible.
It is technically possible to modify the key of an entity as it is
being
converted to a protocol buffer message before it is sent to the
datastore.
You could do this using hooks in the API proxy as described in this
article:http://code.google.com/appengine/articles/hooks.htmlAlsoit is
possible to
construct the key for the desired object if you know the ID in
advance.
class X(db.Model):
pass
# If you've already created the entity so you have the ID.
x_id = X().put().id()
# Instead of getting by ID, you can create the key manually.
k = db.Key.from_path('X', x_id)
Now you have the desired key without having fetched the object, but
the part
which the model class does not allow is setting the key yourself. So
you
could modify the protocol buffer message before it is written to the
datastore, but I don't recommend it.
The decision to allow setting key_names but not IDs is something we
may
revisit.
Happy coding,
Jeff
2009/6/12 cryb cbuti...@gmail.com
Hi.. that is to build key names... What I asked was why I can't
build
a key ID..
On Jun 12, 5:35 am, Antoniov nio@gmail.com wrote:
Use the code:
s = Story(key_name=xzy123)
Then you create an entity with the key name xzy123.
Check this:
http://code.google.com/intl/en-US/appengine/docs/python/datastore/key...
On 6月12日, 上午1时28分, cryb cbuti...@gmail.com wrote:
Does anyone know why it is possible to build a key name but NOT
a key
id? I know key IDs are used as autoincrements, but why can't I
just
override this mechanism and build my own key id?
Suppose I want to overwrite an existent entry in my table that
has a
key id I know, and also I want to keep that key id after
update...
because I can't just build a key id, I am forced to fetch that
entity,
modify it and write it back, instead of just write the updated
entity
with the key id I already know - so an additional read to the
datastore.
Is there an obscure reason for that? (both key names and key ids
are
prefixed with appid/kind as far as I know so there is no chance
of
collision with other apps/kinds)
--~--~-~--~~~---~--~~
You received this message because you are subscribed to the Google Groups
Google App Engine group.
To post to this group, send email to google-appengine@googlegroups.com
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For more options, visit this
[google-appengine] Re: why there is no way to build a key id?
see also
http://groups.google.com/group/google-appengine/browse_thread/thread/3f8cfeaf7dc2eb72/d5d599180fe47e02?lnk=gstq=ryan+allocate#d5d599180fe47e02
On Jun 24, 11:33 am, Jeff S (Google) j...@google.com wrote:
Hi Jeff,
This is an idea that we're aware of as well. If you could reserve the next
ID in advance, then you could actually do this in one put since multiple
entities could be sent in one batch :-) The workaround available now is to
use the key_name, but the difficulty becomes ensuring that the key_name is
unique. Here is a feature request which I'm aware of which is along these
lines (though the approach differs slightly):
http://code.google.com/p/googleappengine/issues/detail?id=1003
Thank you,
Jeff
2009/6/24 Jeff Enderwick jeff.enderw...@gmail.com
Hey Jeff - sorry for the confusion. The idea was that one would be
able to get the unique id from an GOOG and then do a db.put with that
id as an arg. For example, let's say I want to create two entities,
with each referring to each other. I need to do three db.put
operations:
a = Foo()
db.put(a)
b = Foo()
b.ref = a.key()
db.put(b)
a.ref = b.key()
db.put(a)
One would hope to be able to do this with two db.puts.
Thanks,
Jeff
2009/6/16 Jeff S (Google) j...@google.com:
The datastore does not allow key_names which begin with a digit in
order to avoid confusion with an ID, which is numerical. If you want
to use numeric key names, you could add a one letter prefix :-)
Happy coding,
Jeff
On Jun 16, 1:17 am, cryb cbuti...@gmail.com wrote:
Hi Jeff.
Thanks for your reply.. I really hope that in the near future
appengine will support setting key ids for entities.
You mentioned that I can use hooks in order to achieve my goal..
However I was more interested in a solution based on appengine java
sdk, and not on python hooks. Does appengine java sdk provide hooks or
some other similar mechanism?
It seems that for the moment I'll stick to generating key names.
One more question: I've tried to generate some entities with key names
on my local devappserver and I got a strange exception stating that I
can't create key names that start with a digit (?!?)... this holds on
google appengine production servers too or it's just a bug of
devappserver?
Thanks
On Jun 16, 2:45 am, Jeff S (Google) j...@google.com wrote:
Hi cryb,
As you noted, we do not currently allow the ID for a key to be set, as
we
ensure that the ID is unique for each existing entity. I recommend
using a
key name instead of an ID, as Antoniov suggeted, if possible.
It is technically possible to modify the key of an entity as it is
being
converted to a protocol buffer message before it is sent to the
datastore.
You could do this using hooks in the API proxy as described in this
article:http://code.google.com/appengine/articles/hooks.htmlAlsoitis
possible to
construct the key for the desired object if you know the ID in
advance.
class X(db.Model):
pass
# If you've already created the entity so you have the ID.
x_id = X().put().id()
# Instead of getting by ID, you can create the key manually.
k = db.Key.from_path('X', x_id)
Now you have the desired key without having fetched the object, but
the part
which the model class does not allow is setting the key yourself. So
you
could modify the protocol buffer message before it is written to the
datastore, but I don't recommend it.
The decision to allow setting key_names but not IDs is something we
may
revisit.
Happy coding,
Jeff
2009/6/12 cryb cbuti...@gmail.com
Hi.. that is to build key names... What I asked was why I can't
build
a key ID..
On Jun 12, 5:35 am, Antoniov nio@gmail.com wrote:
Use the code:
s = Story(key_name=xzy123)
Then you create an entity with the key name xzy123.
Check this:
http://code.google.com/intl/en-US/appengine/docs/python/datastore/key...
On 6月12日, 上午1时28分, cryb cbuti...@gmail.com wrote:
Does anyone know why it is possible to build a key name but NOT
a key
id? I know key IDs are used as autoincrements, but why can't I
just
override this mechanism and build my own key id?
Suppose I want to overwrite an existent entry in my table that
has a
key id I know, and also I want to keep that key id after
update...
because I can't just build a key id, I am forced to fetch that
entity,
modify it and write it back, instead of just write the updated
entity
with the key id I already know - so an additional read to the
datastore.
Is there an obscure reason for that? (both key names and key ids
are
prefixed with appid/kind as far as I know so there is no chance
of
collision with other apps/kinds)- Hide quoted text -
- Show quoted text -
[google-appengine] Re: why there is no way to build a key id?
Hi Jeff.
Thanks for your reply.. I really hope that in the near future
appengine will support setting key ids for entities.
You mentioned that I can use hooks in order to achieve my goal..
However I was more interested in a solution based on appengine java
sdk, and not on python hooks. Does appengine java sdk provide hooks or
some other similar mechanism?
It seems that for the moment I'll stick to generating key names.
One more question: I've tried to generate some entities with key names
on my local devappserver and I got a strange exception stating that I
can't create key names that start with a digit (?!?)... this holds on
google appengine production servers too or it's just a bug of
devappserver?
Thanks
On Jun 16, 2:45 am, Jeff S (Google) j...@google.com wrote:
Hi cryb,
As you noted, we do not currently allow the ID for a key to be set, as we
ensure that the ID is unique for each existing entity. I recommend using a
key name instead of an ID, as Antoniov suggeted, if possible.
It is technically possible to modify the key of an entity as it is being
converted to a protocol buffer message before it is sent to the datastore.
You could do this using hooks in the API proxy as described in this
article:http://code.google.com/appengine/articles/hooks.htmlAlso it is
possible to
construct the key for the desired object if you know the ID in advance.
class X(db.Model):
pass
# If you've already created the entity so you have the ID.
x_id = X().put().id()
# Instead of getting by ID, you can create the key manually.
k = db.Key.from_path('X', x_id)
Now you have the desired key without having fetched the object, but the part
which the model class does not allow is setting the key yourself. So you
could modify the protocol buffer message before it is written to the
datastore, but I don't recommend it.
The decision to allow setting key_names but not IDs is something we may
revisit.
Happy coding,
Jeff
2009/6/12 cryb cbuti...@gmail.com
Hi.. that is to build key names... What I asked was why I can't build
a key ID..
On Jun 12, 5:35 am, Antoniov nio@gmail.com wrote:
Use the code:
s = Story(key_name=xzy123)
Then you create an entity with the key name xzy123.
Check this:
http://code.google.com/intl/en-US/appengine/docs/python/datastore/key...
On 6月12日, 上午1时28分, cryb cbuti...@gmail.com wrote:
Does anyone know why it is possible to build a key name but NOT a key
id? I know key IDs are used as autoincrements, but why can't I just
override this mechanism and build my own key id?
Suppose I want to overwrite an existent entry in my table that has a
key id I know, and also I want to keep that key id after update...
because I can't just build a key id, I am forced to fetch that entity,
modify it and write it back, instead of just write the updated entity
with the key id I already know - so an additional read to the
datastore.
Is there an obscure reason for that? (both key names and key ids are
prefixed with appid/kind as far as I know so there is no chance of
collision with other apps/kinds)
--~--~-~--~~~---~--~~
You received this message because you are subscribed to the Google Groups
Google App Engine group.
To post to this group, send email to google-appengine@googlegroups.com
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google-appengine+unsubscr...@googlegroups.com
For more options, visit this group at
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-~--~~~~--~~--~--~---
[google-appengine] Re: why there is no way to build a key id?
The decision to allow setting key_names but not IDs is something we may
revisit.
I hope that you're also considering some way to request and allocate
an unused id for a given path prefix. (That way we can get unique key
ids to specify.)
On Jun 15, 4:45 pm, Jeff S (Google) j...@google.com wrote:
Hi cryb,
As you noted, we do not currently allow the ID for a key to be set, as we
ensure that the ID is unique for each existing entity. I recommend using a
key name instead of an ID, as Antoniov suggeted, if possible.
It is technically possible to modify the key of an entity as it is being
converted to a protocol buffer message before it is sent to the datastore.
You could do this using hooks in the API proxy as described in this
article:http://code.google.com/appengine/articles/hooks.htmlAlso it is
possible to
construct the key for the desired object if you know the ID in advance.
class X(db.Model):
pass
# If you've already created the entity so you have the ID.
x_id = X().put().id()
# Instead of getting by ID, you can create the key manually.
k = db.Key.from_path('X', x_id)
Now you have the desired key without having fetched the object, but the part
which the model class does not allow is setting the key yourself. So you
could modify the protocol buffer message before it is written to the
datastore, but I don't recommend it.
The decision to allow setting key_names but not IDs is something we may
revisit.
Happy coding,
Jeff
2009/6/12 cryb cbuti...@gmail.com
Hi.. that is to build key names... What I asked was why I can't build
a key ID..
On Jun 12, 5:35 am, Antoniov nio@gmail.com wrote:
Use the code:
s = Story(key_name=xzy123)
Then you create an entity with the key name xzy123.
Check this:
http://code.google.com/intl/en-US/appengine/docs/python/datastore/key...
On 6月12日, 上午1时28分, cryb cbuti...@gmail.com wrote:
Does anyone know why it is possible to build a key name but NOT a key
id? I know key IDs are used as autoincrements, but why can't I just
override this mechanism and build my own key id?
Suppose I want to overwrite an existent entry in my table that has a
key id I know, and also I want to keep that key id after update...
because I can't just build a key id, I am forced to fetch that entity,
modify it and write it back, instead of just write the updated entity
with the key id I already know - so an additional read to the
datastore.
Is there an obscure reason for that? (both key names and key ids are
prefixed with appid/kind as far as I know so there is no chance of
collision with other apps/kinds)- Hide quoted text -
- Show quoted text -
--~--~-~--~~~---~--~~
You received this message because you are subscribed to the Google Groups
Google App Engine group.
To post to this group, send email to google-appengine@googlegroups.com
To unsubscribe from this group, send email to
google-appengine+unsubscr...@googlegroups.com
For more options, visit this group at
http://groups.google.com/group/google-appengine?hl=en
-~--~~~~--~~--~--~---
[google-appengine] Re: why there is no way to build a key id?
I second that. I have cases where I'm building a structure of multiple
objects, and I have to do a put() just to get the id, and then I need
to do another put() to the same object later on. Eliminating the 2nd
put() of the same object in the flow would also allow me to wrap it in
a transaction.
2009/6/16 Andy Freeman ana...@earthlink.net:
The decision to allow setting key_names but not IDs is something we may
revisit.
I hope that you're also considering some way to request and allocate
an unused id for a given path prefix. (That way we can get unique key
ids to specify.)
On Jun 15, 4:45 pm, Jeff S (Google) j...@google.com wrote:
Hi cryb,
As you noted, we do not currently allow the ID for a key to be set, as we
ensure that the ID is unique for each existing entity. I recommend using a
key name instead of an ID, as Antoniov suggeted, if possible.
It is technically possible to modify the key of an entity as it is being
converted to a protocol buffer message before it is sent to the datastore.
You could do this using hooks in the API proxy as described in this
article:http://code.google.com/appengine/articles/hooks.htmlAlso it is
possible to
construct the key for the desired object if you know the ID in advance.
class X(db.Model):
pass
# If you've already created the entity so you have the ID.
x_id = X().put().id()
# Instead of getting by ID, you can create the key manually.
k = db.Key.from_path('X', x_id)
Now you have the desired key without having fetched the object, but the part
which the model class does not allow is setting the key yourself. So you
could modify the protocol buffer message before it is written to the
datastore, but I don't recommend it.
The decision to allow setting key_names but not IDs is something we may
revisit.
Happy coding,
Jeff
2009/6/12 cryb cbuti...@gmail.com
Hi.. that is to build key names... What I asked was why I can't build
a key ID..
On Jun 12, 5:35 am, Antoniov nio@gmail.com wrote:
Use the code:
s = Story(key_name=xzy123)
Then you create an entity with the key name xzy123.
Check this:
http://code.google.com/intl/en-US/appengine/docs/python/datastore/key...
On 6月12日, 上午1时28分, cryb cbuti...@gmail.com wrote:
Does anyone know why it is possible to build a key name but NOT a key
id? I know key IDs are used as autoincrements, but why can't I just
override this mechanism and build my own key id?
Suppose I want to overwrite an existent entry in my table that has a
key id I know, and also I want to keep that key id after update...
because I can't just build a key id, I am forced to fetch that entity,
modify it and write it back, instead of just write the updated entity
with the key id I already know - so an additional read to the
datastore.
Is there an obscure reason for that? (both key names and key ids are
prefixed with appid/kind as far as I know so there is no chance of
collision with other apps/kinds)- Hide quoted text -
- Show quoted text -
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[google-appengine] Re: why there is no way to build a key id?
The datastore does not allow key_names which begin with a digit in
order to avoid confusion with an ID, which is numerical. If you want
to use numeric key names, you could add a one letter prefix :-)
Happy coding,
Jeff
On Jun 16, 1:17 am, cryb cbuti...@gmail.com wrote:
Hi Jeff.
Thanks for your reply.. I really hope that in the near future
appengine will support setting key ids for entities.
You mentioned that I can use hooks in order to achieve my goal..
However I was more interested in a solution based on appengine java
sdk, and not on python hooks. Does appengine java sdk provide hooks or
some other similar mechanism?
It seems that for the moment I'll stick to generating key names.
One more question: I've tried to generate some entities with key names
on my local devappserver and I got a strange exception stating that I
can't create key names that start with a digit (?!?)... this holds on
google appengine production servers too or it's just a bug of
devappserver?
Thanks
On Jun 16, 2:45 am, Jeff S (Google) j...@google.com wrote:
Hi cryb,
As you noted, we do not currently allow the ID for a key to be set, as we
ensure that the ID is unique for each existing entity. I recommend using a
key name instead of an ID, as Antoniov suggeted, if possible.
It is technically possible to modify the key of an entity as it is being
converted to a protocol buffer message before it is sent to the datastore.
You could do this using hooks in the API proxy as described in this
article:http://code.google.com/appengine/articles/hooks.htmlAlsoit is
possible to
construct the key for the desired object if you know the ID in advance.
class X(db.Model):
pass
# If you've already created the entity so you have the ID.
x_id = X().put().id()
# Instead of getting by ID, you can create the key manually.
k = db.Key.from_path('X', x_id)
Now you have the desired key without having fetched the object, but the part
which the model class does not allow is setting the key yourself. So you
could modify the protocol buffer message before it is written to the
datastore, but I don't recommend it.
The decision to allow setting key_names but not IDs is something we may
revisit.
Happy coding,
Jeff
2009/6/12 cryb cbuti...@gmail.com
Hi.. that is to build key names... What I asked was why I can't build
a key ID..
On Jun 12, 5:35 am, Antoniov nio@gmail.com wrote:
Use the code:
s = Story(key_name=xzy123)
Then you create an entity with the key name xzy123.
Check this:
http://code.google.com/intl/en-US/appengine/docs/python/datastore/key...
On 6月12日, 上午1时28分, cryb cbuti...@gmail.com wrote:
Does anyone know why it is possible to build a key name but NOT a key
id? I know key IDs are used as autoincrements, but why can't I just
override this mechanism and build my own key id?
Suppose I want to overwrite an existent entry in my table that has a
key id I know, and also I want to keep that key id after update...
because I can't just build a key id, I am forced to fetch that entity,
modify it and write it back, instead of just write the updated entity
with the key id I already know - so an additional read to the
datastore.
Is there an obscure reason for that? (both key names and key ids are
prefixed with appid/kind as far as I know so there is no chance of
collision with other apps/kinds)
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[google-appengine] Re: why there is no way to build a key id?
Hi cryb,
As you noted, we do not currently allow the ID for a key to be set, as we
ensure that the ID is unique for each existing entity. I recommend using a
key name instead of an ID, as Antoniov suggeted, if possible.
It is technically possible to modify the key of an entity as it is being
converted to a protocol buffer message before it is sent to the datastore.
You could do this using hooks in the API proxy as described in this article:
http://code.google.com/appengine/articles/hooks.html Also it is possible to
construct the key for the desired object if you know the ID in advance.
class X(db.Model):
pass
# If you've already created the entity so you have the ID.
x_id = X().put().id()
# Instead of getting by ID, you can create the key manually.
k = db.Key.from_path('X', x_id)
Now you have the desired key without having fetched the object, but the part
which the model class does not allow is setting the key yourself. So you
could modify the protocol buffer message before it is written to the
datastore, but I don't recommend it.
The decision to allow setting key_names but not IDs is something we may
revisit.
Happy coding,
Jeff
2009/6/12 cryb cbuti...@gmail.com
Hi.. that is to build key names... What I asked was why I can't build
a key ID..
On Jun 12, 5:35 am, Antoniov nio@gmail.com wrote:
Use the code:
s = Story(key_name=xzy123)
Then you create an entity with the key name xzy123.
Check this:
http://code.google.com/intl/en-US/appengine/docs/python/datastore/key...
On 6月12日, 上午1时28分, cryb cbuti...@gmail.com wrote:
Does anyone know why it is possible to build a key name but NOT a key
id? I know key IDs are used as autoincrements, but why can't I just
override this mechanism and build my own key id?
Suppose I want to overwrite an existent entry in my table that has a
key id I know, and also I want to keep that key id after update...
because I can't just build a key id, I am forced to fetch that entity,
modify it and write it back, instead of just write the updated entity
with the key id I already know - so an additional read to the
datastore.
Is there an obscure reason for that? (both key names and key ids are
prefixed with appid/kind as far as I know so there is no chance of
collision with other apps/kinds)
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You received this message because you are subscribed to the Google Groups
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[google-appengine] Re: why there is no way to build a key id?
Hi.. that is to build key names... What I asked was why I can't build a key ID.. On Jun 12, 5:35 am, Antoniov nio@gmail.com wrote: Use the code: s = Story(key_name=xzy123) Then you create an entity with the key name xzy123. Check this:http://code.google.com/intl/en-US/appengine/docs/python/datastore/key... On 6月12日, 上午1时28分, cryb cbuti...@gmail.com wrote: Does anyone know why it is possible to build a key name but NOT a key id? I know key IDs are used as autoincrements, but why can't I just override this mechanism and build my own key id? Suppose I want to overwrite an existent entry in my table that has a key id I know, and also I want to keep that key id after update... because I can't just build a key id, I am forced to fetch that entity, modify it and write it back, instead of just write the updated entity with the key id I already know - so an additional read to the datastore. Is there an obscure reason for that? (both key names and key ids are prefixed with appid/kind as far as I know so there is no chance of collision with other apps/kinds) --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Google App Engine group. To post to this group, send email to google-appengine@googlegroups.com To unsubscribe from this group, send email to google-appengine+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en -~--~~~~--~~--~--~---
[google-appengine] Re: why there is no way to build a key id?
Use the code: s = Story(key_name=xzy123) Then you create an entity with the key name xzy123. Check this: http://code.google.com/intl/en-US/appengine/docs/python/datastore/keysandentitygroups.html On 6月12日, 上午1时28分, cryb cbuti...@gmail.com wrote: Does anyone know why it is possible to build a key name but NOT a key id? I know key IDs are used as autoincrements, but why can't I just override this mechanism and build my own key id? Suppose I want to overwrite an existent entry in my table that has a key id I know, and also I want to keep that key id after update... because I can't just build a key id, I am forced to fetch that entity, modify it and write it back, instead of just write the updated entity with the key id I already know - so an additional read to the datastore. Is there an obscure reason for that? (both key names and key ids are prefixed with appid/kind as far as I know so there is no chance of collision with other apps/kinds) --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Google App Engine group. To post to this group, send email to google-appengine@googlegroups.com To unsubscribe from this group, send email to google-appengine+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en -~--~~~~--~~--~--~---
