Package @sap/cds for Node.js

[ulyssesbonfim]

Hello folks,

I'm building an app on Cloud Platform (CF) using Node.js/Express. This thing has a /db module containing a entity definition (books-model.cds) and /srv that runs a node.js app on server.js that should read data declared on db module.

According to this documentation the package @sap/cds should help me do exactly that, using the statements below:

cds.importEntities([
    { $entity: "xsds.test.cds::ds_test.e1" },
    { $entity: "xsds.test.cds::ds_test.e2",
      $fields: {
          a: { $association: "xsds.test.cds::ds_test.e2",
               $viaBacklink: "b" }
      }
    }
], callback);
function callback(error, entities) {
    var E1 = entities["xsds.test.cds::ds_test.e1"];
    var E2 = entities["xsds.test.cds::ds_test.e2"];
    // ...
}

Thing is, @sap/cds module v2.10 doesn't seem to think that it is responsible for doing that. This version only handles the build and deployment of .cds files (to hdbcds et etc).

In a old version of this module, before going to npm repository, it was called "sap-cds" and it did provided this .importEntity method.

Does someone know what would be the equivalent of sap-cds on npm.sap.com, or even if it exists?

So far, I'm able to interact with the database using @sap/xsenv and @sap/hdbext.

import xsenv = require('@sap/xsenv') import hdbext = require('@sap/hdbext')    
const services = xsenv.getServices({ hana:'plcockpit-hdi' }) 

express.use('/', hdbext.middleware(services.hana))    
express.get('/', (req, res) => {
        req.db.exec('SELECT * FROM \"com.acme::MyLibrary.Books\"', function (err, rows) {
            res.json({
                result: JSON.stringify(rows[0])
            })
        })
    })

(Code is a simplified version of the original)

Although it works, I would like to know if is there a more "high-level" api to interact with the CDS layer.

Thanks

[former_member635061]

Hello,

I have my project, using Node.js and CDS deployed on Cloud Floundry, developed using WebIDE, and I keep getting this error after trying to use the ORM inside the "@sap/cds" package.

sh: 1: node-pre-gyp: Permission denied
npm ERR! code ELIFECYCLE
npm ERR! errno 126
npm ERR! sqlite3@4.1.0 install: `node-pre-gyp install --fallback-to-build`
npm ERR! Exit status 126
npm ERR! 
npm ERR! Failed at the sqlite3@4.1.0 install script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.
npm ERR! A complete log of this run can be found in:
npm ERR!     /home/vcap/.npm/_logs/2019-10-07T14_14_09_536Z-debug.log
       **ERROR** Unable to build dependencies: exit status 126
Failed to compile droplet: Failed to run all supply scripts: exit status 14
Exit status 223

[Former Member]

Hi Ulysses,

have you solved the problem? I'm facing the same problem and basically i'm not able to use CDS api following the documenation.

Tks.

Daniele.

[ulyssesbonfim]

Hi Daniele,

No, the problem is still open. The workaround is to use @sap/xsenv and @sap/hdbext to read from DB directly.

I can't find an official tutorial on it, but you can find a sample code from here.

Hope this helps