[Toaster] question on spec for "Package included in ..."
Damian, Alexandru
alexandru.damian at intel.com
Tue Jan 14 07:53:04 PST 2014
About Querysets - the querysets are lazy evaluated ! This means that if
you do
a = Build.objects.all()
print a
you'll get the queryset definition. In order to see the actual results, you
need to force the evaluation, either by iterating, or calling it in a list
context.
See
https://docs.djangoproject.com/en/dev/ref/models/querysets/#when-querysets-are-evaluated
Alex
On Tue, Jan 14, 2014 at 3:50 PM, Damian, Alexandru <
alexandru.damian at intel.com> wrote:
> If you do "python ../bitbake/lib/toaster/manage.py shell" you get dumped
> to a Python shell with all the settings done.
>
> You can do "from orm.models import Build", for example, and then play
> directly with "Build.objects.filter()".
>
> My pointer above is that you can reduce the 1, then N queries to just 2
> queries by selecting the IDs in the first query, and then selecting the
> objects based on an id list in the second query. I'm still trying to work
> out the direct query mapping for the many-to-many relationship.
>
> Alex
>
>
> On Tue, Jan 14, 2014 at 3:20 PM, Lerner, Dave <dave.lerner at windriver.com>wrote:
>
>> Hi Alex,
>>
>>
>>
>> Thanks for the pointer. the docs path should use ‘1.5’ not ‘en’.
>>
>>
>>
>> I will work out the Django model syntax for a many-to-many join either
>> before my first commit or as an action item for my 2nd commit since I’m
>> anxious to get the first commit reviewed and it seems to be a general
>> problem that we may want to implement in other templates.
>>
>>
>>
>> Working with the database and models from the python interpreter will
>> help. Do you do that? Are there tricks?
>>
>>
>>
>> Dave Lerner
>>
>>
>>
>> *From:* Damian, Alexandru [mailto:alexandru.damian at intel.com]
>> *Sent:* Monday, January 13, 2014 2:28 PM
>> *To:* Lerner, Dave
>> *Cc:* toaster at yoctoproject.org; Ravi Chintakunta (
>> ravi.chintakunta at timesys.com); Reyna, David
>> *Subject:* Re: question on spec for "Package included in ..."
>>
>>
>>
>> Hi,
>>
>>
>> Just a quick pointer, although I haven't used anything here.
>>
>> https://docs.djangoproject.com/en/dev/topics/db/examples/many_to_many/
>>
>> Django supports many to many queries, I'm gonna try tomorrow to get
>> some code working.
>>
>> Cheers,
>>
>> Alex
>>
>>
>>
>> On Mon, Jan 13, 2014 at 6:54 PM, Lerner, Dave <dave.lerner at windriver.com>
>> wrote:
>>
>> Hi Alex,
>>
>>
>> >
>> > You should try not to think in terms of SQL queries, but instead in
>> terms of Django
>> > QuerySet queries.
>> >
>> > The reason for this is that the SQL is often not portable across
>> different database
>> > backends, which is a requirement for Toaster because we want to give
>> infrastructure
>> > maintainers freedom on how they install Toaster and which db backends
>> they use.
>>
>> The query in question is not required any longer after Belen's answer. I
>> didn't know multiple images per build-id were possible.
>>
>> However, to get a list of a package's dependent packages' names, across a
>> many-to-many relation, in package.html, given a package id, you use two
>> queries to print dependent package names in the template, due to the
>> many-to-many relation...
>> the reverse lookup :
>> {% for d in package.package_dependencies_source.all %}
>>
>> and then the implicit query from package dependency back to package
>> <a href="#{{d.name}}">{{d.depends_on.name}}</a><br/>
>>
>> The standard sql-92 query syntax below will construct a list of package
>> names of dependent packages in a single query rather than the iteration
>> technique above in the package.html template.
>>
>>
>> 'SELECT
>> orm_package_dependency.id,
>> orm_package.name name,
>> orm_package.version version,
>> orm_package.size size
>> FROM
>> orm_package,
>> orm_package_dependency
>> WHERE
>> orm_package_dependency.package_id = %s
>> AND orm_package_dependency.dep_type == 0
>> AND orm_package.id = orm_package_dependency.depends_on_id
>> ', [package_id])
>>
>> I want to use django model query apis because, as you mention, we can't
>> easily validate whether a query is sql-92 and portable.
>>
>> I got as far as getting the set of package_dependencies for RDEPENDS
>> packages on somePackageKey
>> package = Package.get(id=somePackageKey)
>> package_dependencies =
>> package.package_dependencies_source(dep_type_exact=0)
>> but couldn't work out syntax to get from this Package_Dependency set to
>> the Package set without iteration in either the client or server. Do you
>> have a trick other than iterating through this list (in either the server
>> or ugh-client?)
>>
>> -Dave
>>
>>
>> > The Django QuerySet to get the list of targets for a package can be
>> derived by following
>> > the relationship across models; i.e you get the build for the specific
>> package, and then
>> > you get the targets that are images for that build; i.e.
>> >
>> >
>> > > package = Package.objects.filter(pk = id)
>> >
>> > > targets = package.build.target_set.filter(is_image=True)
>> >
>>
>> > What happens here ?
>> > For the package model, build is a foreign key to the Build table, so
>> Django will
>> > populate the instance field with the correct object for Build loaded
>> from the database.
>> >
>> > The reverse dependency through a ForeignKey (i.e. many-to-one
>> relationship) is to be
>> > followed by convention: convert the desired object set model name to
>> lower case, and add
>> > "_set" to the name. This will create a RelatedManager which is
>> basically a QuerySet that
>> > can be filtered at will.
>> >
>> > The reverse dependency naming convention can be overridden by
>> specifying a
>> > "related_name" kwarg in the field model definition; this is needed when
>> you have two
>> > many-to-one relationships with the same object type, i.e. when you map
>> a many-to-many
>> > relationship, e.g. dependency tables.
>> >
>> > Cheers,
>> >
>> > Alex
>> >
>> >
>> >
>> >
>> >
>> >
>> > On Mon, Jan 13, 2014 at 10:50 AM, Barros Pena, Belen <
>> belen.barros.pena at intel.com>
>> > wrote:
>> >
>> >
>> >
>> >
>> > On 12/01/2014 20:45, "Lerner, Dave" <dave.lerner at windriver.com>
>> wrote:
>> >
>> > >Hi Belen, Alex
>> > >
>> > >I have a question about the intent of the specification on page
>> 5 of 10
>> > >of spec design-1.5.1-package-details.pdf listing the images
>> > > that a package is included in.
>> > >
>> > >Packages included in target image
>> > >If
>> > > the package is installed in a build target image, the '1.5.1
>> > >Package
>> > > details' left content column shows only a list of
>> > >the
>> > > target images that include the package.
>> > >Each
>> > > target image is a link to the corresponding '1.1.1
>> > >Included
>> > > package details' page.
>> > >If
>> > > there is more than one target image in the build, they
>> > >are
>> > > separated by commas, and listed in ascending
>> > >alphabetical
>> > > order.
>> > >
>> > >
>> > >
>> > >
>> >
>> > >The list that should appear is clearly for the package
>> > >name-version-revision, but should it be a list restricted (as
>> implied by
>> > > the breadcrumbs) to a single machine/bsp, for example atom-pc vs
>> > >qemuarm?
>> >
>> >
>> > The list includes only the targets of the selected build. Since
>> there is a
>> > one to one relationship between builds and machines (you can only
>> build
>> > for one machine at a time), the answer is yes, the targets listed
>> will
>> > only apply to one machine. I'll try to explain a bit better: in
>> the
>> > example shown in the spec (the one you have attached in your
>> e-mail) you
>> > have selected, from your list of builds, a build for atom-pc that
>> > completed on 11th Jun 2013 at 15:22. That build built 3 targets:
>> > core-image-sato, core-image-sato-sdk and core-image-x11, all of
>> them for a
>> > single machine (atom-pc). The package you have selected
>> (base_files) was
>> > installed in all 3 targets, and so the 3 of them are listed at
>> the top of
>> > the page.
>> >
>> > I hope this makes sense. If you have any questions, let me know.
>> I'll let
>> > Alex answer the implementation part.
>> >
>> > Cheers
>> >
>> > Belén
>> >
>> >
>> > >Do I understand the view spec correctly?
>> > >
>> > >For that case, the current form of the database requires a
>> complicated
>> > >query. I think the logic would have to be (for a passed in
>> > > build-id-arg, package-id-arg)
>> > >·
>> > >Get the machine,
>> > >buildMachine, for this build-id-arg
>> > >·
>> > >Get a list of package.id¹s for this list of
>> > >build.id¹s with this buildMachine
>> > >·
>> > >Get a list of target-installed-package.target_ids¹s that are in
>> the
>> > >include the
>> > >package.id¹s above
>> > >·
>> > >Return a list of distinct
>> > >target.target using the target-insalled-package.target_ids list
>> above and
>> > >also have
>> > >target.is_image true (1)
>> > >
>> > >or using $var embedded
>> > >sql syntax (for C), after buildMachine,
>> > >packageName, packageVersion,
>> > >packageRevision are retrieved...
>> > >
>> > >select distinct(orm_target.target) from
>> > >orm_target, orm_target_installed_package
>> > >where
>> > >
>> > >orm_target.is_image = 1
>> > >and orm_target.id =
>> > >orm_target_installed_package.target_id
>> > >and
>> > >orm_target_installed_package.package_id in
>> > >(select orm_package.id from
>> > >orm_build, orm_package
>> > >where
>> > >
>> > >orm_build.machine = $buildMachine
>> > >and orm_package.name = $packageName
>> > >and
>> > >orm_package.version = $packageVersion
>> > >and
>> > >orm_package.revision = $packageRevision
>> > >and orm_build.id =
>> > >orm_package.build_id);
>> > >
>> > >Thanks,
>> > >Dave Lerner
>> > >
>> > >
>> >
>> >
>> >
>> >
>> >
>> >
>> > --
>> >
>> > Alex Damian
>> > Yocto Project
>> >
>> > SSG / OTC
>>
>>
>>
>>
>> --
>>
>> Alex Damian
>>
>> Yocto Project
>>
>> SSG / OTC
>>
>
>
>
> --
> Alex Damian
> Yocto Project
> SSG / OTC
>
--
Alex Damian
Yocto Project
SSG / OTC
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