How flexible is the database?

[hartmut bischoff]

Hi altogether,

I'm still working on the Ruby-ORM-Adapter to OrientDB, focussing on the behavior of embedded lists, lightweight edges

In Ruby they are serialized as ordinary Arrays. Thus - they should behave like Arrays in the ORM-Adapter, too.

In Ruby  the method "<<" is used to add an element to an array, thus in activeOrient after initializing the Classes TestMode and LinkClass this code

 59      new_record = TestModel.new_instance ll: [ ]                            # new document with an empty array

 60       (1..9).each do |i|

 61         new_record.ll << LinkClass.new_instance( att: "#{i} attribute" )    

 62         new_record.ll << i

 63       end

creates an Array with 18 Elements:

1 attribute ; 1 ; 2 attribute ; 2 ; 3 attribute ; 3 ; 4 attribute ; 4 ; 5 attribute ; 5 ; 6 attribute ; 6 ; 7 attribute ; 7 ; 8 attribute ; 8 ; 9 attribute ; 9

  

each  link to the LinkClass-Instance  is followed by a Number 

Now the surprise. When checking the Record in Studio I got:

METADATA			PROPERTIES
@rid	@version	@class	ll	created_at	updated_at
#31:0	7	ModelTest	[5,"t",78]	2015-07-31T09:13:14.736 02:00	2015-07-31T09:13:14.736 02:00
#31:1	19	ModelTest	#33:0 #33:1 #33:2 #33:3 #33:4 #33:5 ..More(3)

The Numeric-Items are ignored, only the links are displayed, and only 9 Array-Elements are detected.

However, if I reverse the order of entries (adding first the number then the link), Studio does not recognize the links but displays all elements.

METADATA			PROPERTIES
@rid	@version	@class	ll	created_at	updated_at
#31:0	7	ModelTest	[5,"t",78]	2015-07-31T09:30:43.522 02:00	2015-07-31T09:30:43.522 02:00
#31:1	19	ModelTest	[1,"#33:0",2,"#33:1",3,"#33:2",4,"#33:3",5,"#33:4",6,"#33:5",7,"#33:6",8,"#33:7",9,"#33:8"]

10255010010005000

Am I bending the Datamodel of Orientdb to much or is this just a bug in studio?

[hartmut bischoff]

By further investigating ...

the Array not recognized correctly by Studio can be queried the usual way:

select from (select expand(ll) from ModelTest ) where att like '4%'

returns an Array with expanded TestLinkClasses starting with

{

    "result": [

        {

            "@type": "d",

            "@rid": "#10:3",

            "@version": 1,

            "@class": "TestLinkClass",

            "att": "4 attribute"

        },

Thus I guess that's valid to store unsorted data in an array. And I am able to use the embedded properties in the usual manner, no matter how »chaotic« the array is organized.