Managed associations with XSDS

[Former Member]

Hello all,

i'm sure i've done this before, but i just can't get the key...

I've got this CDS file with these two entities, defined as follows:

@Catalog.tableType: #COLUMN

Entity "group" {

key id: Integer64 not null;

name: Association to model.translation not null;

description: Association to model.translation;

parent: Integer64 null;

editable: Integer not null default 1;

status: Integer not null default 0;

user_id: Association to model.user;

key version: Integer not null default 1;

date: UTCTimestamp not null;

};

@Catalog.tableType: #COLUMN

Entity translation {

key id: Integer64 not null;

en: String(5000);

fr: String(5000);

de: String(5000);

it: String(5000);

es: String(5000);

zh: String(5000);

ko: String(5000);

ru: String(5000);

jv: String(5000);

ar: String(5000);

pt: String(5000);

ja: String(5000);

};

When i see the schema generated with my hdbdd file, i get this:

BIGINT

	1	id		FIXED	(X1)	X
To select row, press SPACEBAR	2	name.id	BIGINT		FIXED		X
To select row, press SPACEBAR	3	description.id	BIGINT		FIXED
To select row, press SPACEBAR	4	parent	BIGINT		FIXED
To select row, press SPACEBAR	5	editable	INTEGER		INT		X	1
To select row, press SPACEBAR	6	status	INTEGER		INT		X	0
To select row, press SPACEBAR	7	user_id.id	BIGINT		FIXED
To select row, press SPACEBAR	8	version	INTEGER		INT	(X2)	X	1
To select row, press SPACEBAR	9	date	TIMESTAMP		LONGDATE		X

So I want to show the name of the group:

        var lang = "en";

        var MyEntity = XSDS.$importEntity("package", "model.group");

        // retrieve entity instance

        var query = MyEntity.$query();

        var results = query.$execute();

        $.response.setBody(JSON.stringify(results[0].name[lang].toString()));

But get this error:

results[0].name[lang] is undefined

i also tried results[0].name.id[lang], and many other things...

i must be missing something here, but i'm getting nuts...

many thanks in advance!

Luis

[pfefferf · Accepted solution]

Hello Luis,

although I do not really understand why you set up your data model as described following can help you.

Instead of var query = ... and var results = ... do following:

var results = $query().$project({name: true}).$execute();

Then you can access the value like you do it (although no JSON stringify and .toString is necessary cause the values in your language columns are already strings).

Regards,

Florian

[Former Member · Accepted solution]

Thank you so much, Florian!

This data model has been set by a third party, who wants me to migrate it to SAP HANA.

The idea is to get the name and description of the group, and display it on different languages, deppending on the parameter "lang".

So it's mandatory the use of projections if you want to get an association, i guess. Because i've been able to access data from a single table without the $project() method. I'm i right?

thank you very much for your help.

Regards,

Luis