> $col:=ds.Client.query("Name = :1";"@"+Self->+"@") .distinct("PriKey")
> EntSel:=ds.Contract.query("to_Client IN :1";$col)
No need for this, just write:
$clients:=ds.Client.query("Name = :1";"@"+Self->+"@")
$contracts:=$clients.Contracts
--
Grüße/Regards,
[heubach-media] | Christian Sakowski
[email protected]
Tel: +49/(0)40/41 455 455
> Am 06.12.2019 um 17:04 schrieb Kirk Brooks via 4D_Tech <[email protected]>:
>
> Keith,
> Neil is dead on in the case of RELATE MANY - you can access this directly
> from the entity via the name of the relation. But you are asking about
> RELATE MANY SELECTION where you have a selection of one-records and you
> want a selection of all the many-records.
>
> Your example works fine - though you don't need the step of converting to
> and from the array:
>
> $clients:=ds.Client.query("Name = :1";"@"+Self->+"@")
> $col:=$clients.distinct("PriKey")
> EntSel:=ds.Contract.query("to_Client IN :1";$col)
>
> By definition the PriKey should be distinct already but there's no downside
> to the command and it will also work for non-distinct values so it's a good
> habit to develop.
>
> I would shorten it to a single query line:
>
> $col:=ds.Client.query("Name = :1";"@"+Self->+"@") .distinct("PriKey")
> EntSel:=ds.Contract.query("to_Client IN :1";$col)
>
>
> This doesn't throw an error if the query is empty. And it's two lines of
> code to replace 7.
>
> I infer you are retro fitting this ORDA code into an existing form because
> of using Self and a process var for EntSel. My experience so far is this is
> the less optimal way to implement ORDA. First, classic 4D is probably doing
> just fine for this chore so carry on with what you've got. Introducing ORDA
> in cases like that usually don't work out great. Your example sort of makes
> this point - if you start thinking the way to solve an ORDA problem is to
> start converting back and forth between arrays you are probably missing
> something new you should be using.
>
> For UI stuff like this that means the object referenced by Self will
> ultimately be better handled if you begin using Form. I like to start from
> scratch when convert a form: make a new blank form. Copy in the most basic
> elements of it and learn to set it up using Form. You will know you're
> doing it right when you stop needing to rely on pointers (especially Self)
> and process variables to manage forms. I stress "rely on" here. Self is
> useful but if you are using ORDA it's the last resort, never the first.
> Process vars have a place but rarely - very rarely - for managing a modern
> 4D form. Learn to use Form instead.
>
> Once you have the basics working, (opening, closing, moving around,
> populating static or semi static objects) start adding in the other
> functionality. As you do that think about what you trying to accomplish -
> what is goal and purpose of the list, listbox, subform, etc. you are adding
> in. And how do you accomplish that with ORDA. This is important because
> whatever that task is accomplishing it with ORDA will nearly always be a
> completely different workflow from accomplishing it in classic 4D. If you
> simply paste in what you've been doing it's not going to really change
> anything. And if you don't want to really change anything what's the point
> of converting to ORDA?
>
> By putting this into a brand new form you eventually get to a point where
> you can compare your new approach to the old head to head. And this also
> makes it easier to swap out the new form for the old in your code.
>
> Hope this helps.
>
> On Thu, Dec 5, 2019 at 12:00 PM kculotta via 4D_Tech <[email protected]>
> wrote:
>
>> Hello,
>>
>> RELATE MANY SELECTION is a convenient way to get a set of related many
>> records.
>> Is there a more succinct or efficient ORDA method than the following to do
>> the same thing?
>>
>> // get Contracts for a group of Clients
>> ARRAY TEXT($array;0)
>> C_COLLECTION($col)
>>
>> $clients:=ds.Client.query("Name = :1";"@"+Self->+"@") // get the clients
>> $col:=$clients.toCollection("PriKey") // make a Collection of Client
>> Primary Keys ("PriKey";"..Value..";"PriKey...)
>> COLLECTION TO ARRAY($col;$array;"PriKey") // make it an array of Primary
>> Keys
>> ARRAY TO COLLECTION($col;$array) // back to a Collection of Text
>> ("..Value..";"..Value..")
>> EntSel:=ds.Contract.query("to_Client IN :1";$col) // search in the
>> Collection
>>
>> Thanks - Keith CDI
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>
>
>
> --
> Kirk Brooks
> San Francisco, CA
> =======================
>
> What can be said, can be said clearly,
> and what you can’t say, you should shut up about
>
> *Wittgenstein and the Computer *
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