Question Re: Get specific amount of data from OData in Technology Q&A

Get specific amount of data from OData

Former Member — Thu, 26 Nov 2015 14:10:24 GMT

Hello,

I consume data from my OData service which I would like to store into JSON. It looks like this:


var oModel = new sap.ui.model.json.JSONModel();
var url = "/Service-url/EntitySet";
oModel.loadData(url,"",false);

But because I'm consuming a huge amount of data I get a Time-Out error.

1. How can I say just give me only 100 fields? How does the code look like for this approach?

Thank you in advance.

Re: Get specific amount of data from OData

karthikarjun — Thu, 26 Nov 2015 15:00:04 GMT

Can you try this

https://sapui5.hana.ondemand.com/sdk/#docs/api/symbols/sap.ui.model.Model.html#setSizeLimit

setSizeLimit(collection)

Regards,

Karthik A

Re: Get specific amount of data from OData

Qualiture — Thu, 26 Nov 2015 15:23:25 GMT

I may sound like a broken record already, but please, do not load OData services in a JSONModel

Use ODataModel instead, it will take care of loading, paging/growing etc

Re: Get specific amount of data from OData

Former Member — Thu, 26 Nov 2015 15:33:08 GMT

Ok, let's switch to an ODataModel. So first I'm going to:


var oModel = new sap.ui.model.odata.ODataModel();

Now let's say I have:

OData Service Url: /ODataServiceUrl/ (which is also already set in manifest if this info is necessary),

EntitySet: /ESSet

Now how can I say just give me 100 records from the "ODataServiceUrl/ESSet". How would you continue from my code above? Can you show the code, please?

Re: Get specific amount of data from OData

Qualiture — Thu, 26 Nov 2015 15:41:57 GMT

Really, if you use ODataModel, you don't need to worry about the number of data, because it will be loaded upon demand (for instance, with a table, it will only load 20 records, but if you scroll or paginate further, it will load more data in a new request)

But if you really want to set a hard stop, use $skip=0&$top=100 in your service URL

Re: Get specific amount of data from OData

Former Member — Thu, 26 Nov 2015 15:54:22 GMT

The reason is that I'm using vizFrame and I set for its path: /ESSet. This will cause a crash. Even the SAP Gateway Client will crash because of the huge amount of data. For this reason I would like to limit the access.

Regarding your Code: I tried it in the Gateway Client like ODataServiceUrl/ESSet$skip=0&$top=100 or ODataServiceUrl/ESSet/$skip=0&$top=100 and it's throwing back a 400/404 Error.

Re: Get specific amount of data from OData

Former Member — Thu, 26 Nov 2015 17:06:19 GMT

Ok, sorry, I forgot to add ? between. Now in the Gateway Client it's working fine but for my app I get a bad-request (400) error. Any clue?

Re: Get specific amount of data from OData

Qualiture — Fri, 27 Nov 2015 08:38:21 GMT

In the browser's network tab, can you check the actual request being made? I suspect it is ill-formatted

Re: Get specific amount of data from OData

Former Member — Fri, 27 Nov 2015 09:18:29 GMT

The request is made and I have to admit that there are several lines of "-.-.-.-.-". Is this the ill-format you are talking about?

Re: Get specific amount of data from OData

Qualiture — Fri, 27 Nov 2015 09:26:01 GMT

Could well be; a 400 error usually means the server receives a request which is not in the expected format, or the (generated) URL to your OData service request is not entirely correct. Check your Gateway logs for an indication of what might be the issue.

Re: Get specific amount of data from OData

Former Member — Mon, 30 Nov 2015 12:19:21 GMT

Hello Robin,

Gateway log says: Invalid system query options value. And the frontend is mentioning a bad request (400 Error).

You know, I try this workarounds to reduce the consumption of data. I implemented a Viz Chart and different to a SmartTable it's consuming whole data coming from my OData Service. These are huge and cause a crash.

Now this workaround is not working:


var oVizDataset = new sap.viz.ui5.data.FlattenedDataset({
  data: {
  path: "/EntitySet?$top=10";
  }
  });

I also tried to do it this way:


var uri = "serviceUrl/"; 
var oModel = new sap.ui.model.odata.ODataModel(uri, true); 
oModel.setSizeLimit(1);

Based on setSizeLimit nothing happens.

So, do you may have an idea? Is this a known issue regarding Viz?