Build OData Queries with the SAP Cloud SDK's Virtual Data Model

This tutorial and the following ones in this group are based on the SAP Cloud SDK’s TypeScript project scaffolding. We have described how to set it up in a previous tutorial. Go ahead and download the project scaffolding as starting point for these tutorials.

For each OData service in SAP S/4HANA Cloud, there is a corresponding npm package in the SAP Cloud SDK. You can find an overview of all packages here. All of the VDM packages are prefixed with @sap/cloud-sdk-vdm. The package for the business partner service can be installed by executing the following command on your command line:

npm install @sap/cloud-sdk-vdm-business-partner-service

Starting with version 1.4.0 of the SAP Cloud SDK for JavaScript, you can also use our generator for your own custom OData services.

Start by creating a file called business-partners-route.ts in the src folder of the project. Copy the following code into the file:

import { Request, Response } from 'express';

export function businessPartnerRoute(req: Request, res: Response) {
  res.status(200).send('Nothing to see yet...');
}

The function businessPartnerRoute is the function that will handle requests to the API endpoint that we create. Every function in Express.js that handles a request takes two parameters: the Request object and the Response object (though we don’t need the Request for now).

Now you need to instruct the Express.js router to delegate incoming requests to /business-partners to the businessPartnerRoute function. To do so, open the application.ts file, import your function and add a route to the router:

import { businessPartnerRoute } from './business-partner-route';

// ...

private routes(): void {
  const router = express.Router();

  router.get("/", indexRoute);
  router.get("/hello", helloWorld);
  // add the following line
  router.get("/business-partners", businessPartnerRoute);
  this.app.use("/", router);
}

Now you can start your app using npm run start:local or npm run serve-debug. When the server is running, you should see Express server listening on port 8080 on your command line. Open http://localhost:8080/business-partners and you should see 'Nothing to see yet...'.

Every request you can do with the VDM follows a common pattern. You start with the entity that you want to perform a request on, in this case BusinessPartner. To build a request, call the requestBuilder function. Next, you can select which request to build. OData, as RESTful API protocol, follows the CRUD model: Create, Read, Update, Delete. For reading, we differentiate between querying the service, where you get all available entities if you don’t specifically restrict the result set, and retrieving a specific entity by its key. The respective functions are called getAll and getByKey. For the remaining requests, the functions are simply called create, update and delete. When you type BusinessPartner.requestBuilder()., your IDE should show which operations are available on the respective entity. For example, it is not possible to delete a business partner via the business partner service. Therefore, the VDM will not offer a delete function.

Following this pattern, update your code as shown below (mind the updated import):

import { Request, Response } from 'express';
import { BusinessPartner } from '@sap/cloud-sdk-vdm-business-partner-service';

export function businessPartnerRoute(req: Request, res: Response) {
  res.status(200).send('Nothing to see yet...');
}

function getAllBusinessPartners(): Promise<BusinessPartner[]> {
  return BusinessPartner.requestBuilder()
    .getAll();
}

Requests can be executed with the execute function. To do this, the request builder needs to know where to send this request, in the form of a Destination. In this tutorial, we will provide this information directly to the execute function. We have described how to integrate with SAP Cloud Platform’s Destination Service in this tutorial. Every destination requires a URL. Note, that we do not need the full URL to the service, but only the host of the system. Suppose, you have an SAP S/4HANA Cloud system running under https://my.s4hana.ondemand.com/, you can pass that information directly to the request builder like this:

import { BusinessPartner } from '@sap/cloud-sdk-vdm-business-partner-service';

function getAllBusinessPartners(): Promise<BusinessPartner[]> {
  return BusinessPartner.requestBuilder()
    .getAll()
    .execute({
      url: 'https://my.s4hana.ondemand.com/'
    });
}

Typically, you will need to authenticate yourself against a system in order to successfully execute a request. If you have a technical user for your system, you can pass the credentials like this:

import { BusinessPartner } from '@sap/cloud-sdk-vdm-business-partner-service';

function getAllBusinessPartners(): Promise<BusinessPartner[]> {
  return BusinessPartner.requestBuilder()
    .getAll()
    .execute({
      url: 'https://my.s4hana.ondemand.com/',
      username: "USERNAME",
      password: "PASSWORD"
    });
}

Alternatively, if you want to use the sandbox of the SAP API Business Hub, you will need to provide an APIKey. withCustomHeaders allows you to add custom HTTP headers to the request. You can pass your API key like this:

import { BusinessPartner } from '@sap/cloud-sdk-vdm-business-partner-service';

function getAllBusinessPartners(): Promise<BusinessPartner[]> {
  return BusinessPartner.requestBuilder()
    .getAll()
    .withCustomHeaders({
      APIKey: 'YOUR-API-KEY'
    })
    .execute({
      url: "https://sandbox.api.sap.com/s4hanacloud/"
    });
}

Like SQL, OData allows to only select specific properties of an entity. For our address manager, we only want to know the ID, the first name and the last name of a business partner. Add a select statement to your request like this:

import { BusinessPartner } from '@sap/cloud-sdk-vdm-business-partner-service';

function getAllBusinessPartners(): Promise<BusinessPartner[]> {
  return BusinessPartner.requestBuilder()
    .getAll()
    .select(
      BusinessPartner.BUSINESS_PARTNER,
      BusinessPartner.FIRST_NAME,
      BusinessPartner.LAST_NAME
    )
    .execute({
      url: 'https://my.s4hana.ondemand.com/'
    });
}

As you can see, each property we select is represented by an object on the BusinessPartner entity. If you type BusinessPartner. in your IDE, you will see all the properties the can be selected on that entity. This saves you from having to look up the properties in the metadata, and prevents errors due to mistyping.

Business partners can either be natural persons or legal persons (e.g. organizations or companies). For the address manager, we only want the addresses of natural persons. Therefore, we need to a filter to our request. Modify your code like this:

import { BusinessPartner } from '@sap/cloud-sdk-vdm-business-partner-service';

function getAllBusinessPartners(): Promise<BusinessPartner[]> {
  return BusinessPartner.requestBuilder()
    .getAll()
    .select(
      BusinessPartner.BUSINESS_PARTNER,
      BusinessPartner.FIRST_NAME,
      BusinessPartner.LAST_NAME
    )
    .filter(
      BusinessPartner.BUSINESS_PARTNER_CATEGORY.equals('1')
    )
    .execute({
      url: 'https://my.s4hana.ondemand.com/'
    });
}

As for select, you can use the properties of the BusinessPartner entity directly for filtering. Each property offers a set of functions for constructing filters. Every property has the equals and nonEquals function. Depending on that type of the property, there can be additional functions like greaterThan or greaterOrEqual. Also, since we know the type of the property, the VDM will prevent your from passing values of the wrong type. For example, BusinessPartner.FIRST_NAME.equals(1) would not compile (in pure JavaScript the code would only fail at runtime, but most editors will still raise a warning for the type mismatch).

While this not required for the address manager, it’s a good time to introduce complex filters. By default, multiple filter statements passed to the filter function will be combined with a logical AND. For example, the following code will only retrieve business partners that are natural persons and whose first name is not “John”:

import { BusinessPartner } from '@sap/cloud-sdk-vdm-business-partner-service';

function getAllBusinessPartners(): Promise<BusinessPartner[]> {
  return BusinessPartner.requestBuilder()
    .getAll()
    .select(
      BusinessPartner.BUSINESS_PARTNER,
      BusinessPartner.FIRST_NAME,
      BusinessPartner.LAST_NAME
    )
    .filter(
      BusinessPartner.BUSINESS_PARTNER_CATEGORY.equals('1'),
      BusinessPartner.FIRST_NAME.notEquals('John')
    )
    .execute({
      url: 'https://my.s4hana.ondemand.com/'
    });
}

However, suppose we also want to retrieve business partners if they have been created in 2019 or later. For such use cases, you can use the and and or functions.

import { and, or } from '@sap/cloud-sdk-core';
import { BusinessPartner } from '@sap/cloud-sdk-vdm-business-partner-service';
import * as moment from 'moment';

function getAllBusinessPartners(): Promise<BusinessPartner[]> {
  return BusinessPartner.requestBuilder()
    .getAll()
    .select(
      BusinessPartner.BUSINESS_PARTNER,
      BusinessPartner.FIRST_NAME,
      BusinessPartner.LAST_NAME
    )
    .filter(
      or(
        BusinessPartner.CREATION_DATE.greaterThan(moment('2019-01-01 00:00:00')),
        and(
          BusinessPartner.BUSINESS_PARTNER_CATEGORY.equals('1'),
          BusinessPartner.FIRST_NAME.notEquals('Joe')
        )
      )
    )
    .execute({
      url: 'https://my.s4hana.ondemand.com/'
    });
}

The OData services in SAP S/4HANA Cloud can be extended by so-called custom fields. A custom field is any property that is not present in the default metadata of a service. Therefore, custom fields are of not “known” to the VDM. However, we still offer the same level of convenience for select and filter.

Suppose you have extended your business partner entity by a field that stores which user has last checked the addresses. You could use this field for selecting and filtering like this:

import { BusinessPartner } from '@sap/cloud-sdk-vdm-business-partner-service';

const ADDR_LAST_CHECKED_BY: CustomField<BusinessPartner> = BusinessPartner.customField('YY1_AddrLastCheckedBy_bus');

BusinessPartner.requestBuilder()
  .getAll()
  .select(
    BusinessPartner.FIRST_NAME,
    BusinessPartner.LAST_NAME,
    ADDR_LAST_CHECKED_BY
  )
  .filter(ADDR_LAST_CHECKED_BY.notEquals('John_Doe'))
  .execute({
    url: 'https://my.s4hana.ondemand.com/'
  });

Every entity offers a set of functions to interact with custom fields. You can get the value of a specific field using the getCustomField function. Alternatively, you can also get an object holding all fields using getCustomFields.

import { BusinessPartner } from '@sap/cloud-sdk-vdm-business-partner-service';

// pre-existing businessPartner

const fieldValue: any = businessPartner.getCustomField('YY1_AddrLastCheckedBy_bus');
const allCustomFields: { [key: string]: any } = businessPartner.getCustomFields();

Note, that the values will always be typed with any. The type of a custom field can be any JSON primitive, i.e. boolean, string, number and null. If there is no custom field with the given name, getCustomField will return undefined. You can check whether a custom field with a given name exists using the hasCustomField function. You can set the value for a custom field using the setCustomField function:

import { BusinessPartner } from '@sap/cloud-sdk-vdm-business-partner-service';

// pre-existing businessPartner

businessPartner.setCustomField('YY1_AddrLastCheckedBy_bus', 'John_Doe');

Note, that you cannot use a field name that already exists. For example, if you would try to use setCustomField('FirstName', 'Joe'), an error would be thrown, because the field FirstName already exists on the business partner entity.

You’ve finished the implementation of getAllBusinessPartners! To make the result available to clients, you need to call the function in businessPartnersRoute and send the result to clients. Update business-partners-route.ts so that it looks like this:

import { Request, Response } from 'express';
import { BusinessPartner } from '@sap/cloud-sdk-vdm-business-partner-service';

export function businessPartnerRoute(req: Request, res: Response) {
  getAllBusinessPartners()
    .then(businessPartners => {
      res.status(200).send(businessPartners);
    })
    .catch(error => {
      res.status(500).send(error.message);
    })
}

function getAllBusinessPartners(): Promise<BusinessPartner[]> {
  return BusinessPartner.requestBuilder()
    .getAll()
    .select(
      BusinessPartner.BUSINESS_PARTNER,
      BusinessPartner.FIRST_NAME,
      BusinessPartner.LAST_NAME
    )
    .filter(
      BusinessPartner.BUSINESS_PARTNER_CATEGORY.equals('1')
    )
    .execute({
      url: 'https://my.s4hana.ondemand.com/'
    });
}

businessPartnerRoute now calls the getAllBusinessPartners, which returns a Promise. A Promise can have two result states. Either the execution of the wrapped function succeeded, or it failed.

The success case can be handled with the then function. This gives you access to the return value of the wrapped function, which is an array of business partners. res.status(200).send(businessPartners) sends a response to the client with HTTP status code 200 and the business partner array as body.

Similarly, the error case is handled with the catch function. Should an error by thrown, we respond with status code 500 and send the error message to the client.

Restart your server and open http://localhost:8080/business-partners. You should see a list of business partners!