In this blog we will fetch data using RFC.

Create RFC using transaction code SE37. ZTEST_RFC_ODATA.

Tables.

Source Code.

FUNCTION ZTEST_RFC_ODATA.
*"----------------------------------------------------------------------
*"*"Local Interface:
*"  IMPORTING
*"     VALUE(CARRID) TYPE  S_CARR_ID
*"  TABLES
*"      ZTEST_RFC_TAB STRUCTURE  ZTEST_RFC OPTIONAL
*"----------------------------------------------------------------------
data:  wa_sCARR type sCARR,
      scarr type TABLE OF scarr,
      ZTEST_RFC TYPE ZTEST_RFC,
      sflight type TABLE OF sflight WITH HEADER LINE.

select * from scarr into TABLE scarr where CARRID = CARRID.

    select * from sflight INTO TABLE sflight WHERE CARRID = CARRID.

      LOOP AT Sflight.

        ZTEST_RFC-CARRID = sflight-CARRID.
        ZTEST_RFC-CONNID = sflight-CONNID.
        ZTEST_RFC-FLDATE = sflight-FLDATE.

        READ TABLE SCARR INTO wa_sCARR WITH KEY CARRID =  ZTEST_RFC-CARRID .
        IF SY-SUBRC = 0.
        ZTEST_RFC-CARRNAME =  wa_scarr-CARRNAME.
        ZTEST_RFC-CURRCODE = wa_scarr-CURRCODE.
        ZTEST_RFC-URL    = wa_scarr-URL.
        ENDIF.

        append ztest_rfc to ztest_rfc_tab.
        CLEAR ztest_rfc.

      ENDLOOP.

ENDFUNCTION.

Select RFC in attribute.

After creating RFC go to Transaction code SEGW. Create Project.

There will be four folders like displayed below.

Click on Data Model . Import -> RFC/BOR Interface.

Give Entity name and fill entries like displayed below.

Click on next of above image and select check boxes below. Look at assign structure column don’t tick checkbox. Keep same as below.

Select key field.

Click on finish and then go to Service Implementation Folder in it go to structure and right click on GetEntitySet and select Map Data Source.

Select proper inputs like below.

Below screen will appear click on propose maping.

It will be display like below.

Now add one row and do mapping like below.Select entry from Data Source Column.

Do mapping like below.

Now Save and Generate project.

Now execute transaction code /iwfnd/maint_service. Click on Add Services.

Fill data like below.

Select entry displayed in above image.

Navigate back to /iwfnd/maint_service screen. Select service go to ICF Node and Activate it.

Now click in SAP Gateway Client, and Execute.

Now select entity set and apply relevant filters.

Execute and you will able to see data.

Link for reference –    /sap/opu/odata/sap/ZTEST_RFC_TEST_SRV/RFCDEMOSet?$filter=Carrid eq ‘AA’

Put cursor on DELETE_ENTITY method and press redefine method.

You will able to see below screen.

Write Below code for delete.

DATA : wa_keytab TYPE /iwbep/s_mgw_name_value_pair.

READ TABLE it_key_tab INTO wa_keytab INDEX 1.

DELETE FROM ZEMPLOYEE_1 WHERE EMP_ID EQ  wa_keytab-value.

COMMIT WORK.

Save and activate class.

Go execute transaction code /IWFND/MAINT_SERVICE ,find technical service name ,Activate using ICF nodes and click on SAP Gateway Client.

Click on EntitySet and pass url (/sap/opu/odata/sap/ZTEST_ODATA2_SRV/EmployeeSet(EmpId=’00000001′).

Put cursor on UPDATE_ENTITY and click on redefine method.

Below screen will appear.

Write below code.

DATA :wa_emp TYPE ZCL_ZTEST_ODATA2_MPC=>TS_EMPLOYEE.

* Capture input value from Frontend into workarea wa_emp 
  CLEAR : wa_emp.
  io_data_provider->read_entry_data( IMPORTING es_data = wa_emp ).

* Here we can use UPDATE or MODIFY depending on the requirement
  UPDATE ZEMPLOYEE_1  SET name = wa_emp-name
                      WHERE emp_id  = wa_emp-emp_id.

    COMMIT WORK.

Save and Activate Method.

Now execute transaction code /IWFND/MAINT_SERVICE find service. Activate ICF node again and click on SAP Gateway Client.

Below screen will appear.

Click on EntitySets.

Get Entity ,Which you need to UPDATE (/sap/opu/odata/sap/ZTEST_ODATA1_SRV/EmployeeSet(EmpId=’00000001′).

Reason is to reuse payload.

Click on Use as Request.

Select Radio Button PUT, keep URL as it is.

Change value of description.

Execute.

Successfully updated Entity From Odata.

Now in next blog we will delete entry from table.

Go to DPC_EXT class in it FIND CREATE_ENTITY method and redefine method.

Below Screen will appear.

Write below code.

DATA : wa_iodp TYPE ZCL_ZTEST_ODATA2_MPC=>TS_EMPLOYEE.
* Capture Input record from frontend into WA_IODP
       io_data_provider->read_entry_data( IMPORTING es_data = wa_iodp ).
* Insert into table ZEMPLOYEE_1 
        INSERT INTO ZEMPLOYEE_1 VALUES wa_iodp.
         COMMIT WORK.
*   Transfer Inserted records to frontend
        er_entity = wa_iodp.

Save and Activate.

Go to Transaction Code /IWFND/MAINT_SERVICE.

Execute it by clicking on SAP Gateway Client.

Below screen will appear.

Click on EntitySets and select EntitySet Name.

First Get Entity Set by using url: /sap/opu/odata/sap/ZTEST_ODATA2_SRV/EmployeeSet(EmpId=’00000001′)

Reason for doing it that we often make mistake while creating payload hence we will fetch one record and will take that record for reference and change values for our operation.

Click on Use as Request.

Below screen will appear.

Select Radio Button Post and change values of key field.

Changed Entry.

Click on Execute ,change URL like /sap/opu/odata/sap/ZTEST_ODATA2_SRV/EmployeeSet than press execute else It will throw error.

Entries are there in Table.

Successfully Created record USING OData. In next blog we will update entry in table.

For this operation we will use method GET_ENTITY of class *DPC_EXT.

Edit class put cursor on GET_ENTITY method and press Redefine Method.

Below screen will appear.

Remove each commented thing in method and write code.

DATA : wa_keytab TYPE /iwbep/s_mgw_name_value_pair.

READ TABLE it_key_tab INTO wa_keytab INDEX 1.

SELECT SINGLE * FROM ZEMPLOYEE_1 INTO er_entity WHERE EMP_ID EQ wa_keytab-value.

Save and activate class.

Execute Transaction Code /IWFND/MAINT_SERVICE

Select service and activate it.

Information message will be displayed like below.

Now click on SAP GateWay client.

Press on EntitySet and select relevant entity set.

Add filter to fetch selected row from table.

We have successfully fetched single row of table , in next blog we will try to update entry of table.

In this blog we will fetch all the data from table in OData service.

Prerequisite – We should have created table with field Emp_ID(Numc , 8) and Name(Char,30).

Right click on Data Model put cursor on import and select DDIC Structure.

Below screen will appear, provide Entity name according your choice and give table name in ABAP structure name.

Once you click on next below screen will appear and select fields which you want to display in service.

Click on next and select key field of table.

Click on finish.

We have imported DDIC structure and now we need to click on generate.

It will create DPC/MPC classes, technical model and service name for your project.

Once you click on right below screen will appear.

Keep on pressing Enter till you see below screen.

In Runtime artifacts folder six methods will be generated, select DPC_EXT method for further operation.

Class screen will appear like below.

Scroll down methods, you will find five important methods named Drop down in method, you will see five important methods CREATE_ENTITY, DELETE_ENTITY, GET_ENTITY, GET_ENTITYSET, UPDATE_ENTITY.We will use these methods for CRUD operation but in this blog we will only focus on GET_ENTITYSET method.

Change class to edit mode (It is in display mode) put cursor on *GET_ENTITYSET method and press redefine method.

Screen will look like below.

Remove all the code and write down query according your requirement. Here, we need to fetch all the data hence we will write below code.

DATA : wa_keytab TYPE /iwbep/s_mgw_name_value_pair.

READ TABLE it_key_tab INTO wa_keytab INDEX 1.

SELECT SINGLE * FROM ZEMPLOYEE_1 INTO er_entity WHERE EMP_ID EQ wa_keytab-value.

Save and Activate class.

Above steps are to select all fields on service. We have created project next step is to activate service. For that we need to execute transaction code /IWFND/MAINT_SERVICE.

Click on Add Service.

Fill details accordingly. System alias will be local and technical service name is your project name which you have created in SEGW.

Click on Get services or press enter.

One entry in backend services will appear now once you click on Technical Service Name it allows you to add service.

Write-down package name and click on right icon.

Below screen will be displayed in sequence.

Now search for your service in /IWFND/MAINT_SERVICE.

Select service and activate it.

Information message will be displayed.

Now, click on SAP gateway client.

Below screen will appear.

Select entity which you have created and execute it.

All data of table will be appear in response. J We have successfully imported DDIC table, created service , activated service and fetched data from that table. Now in next blogs we will perform UPDATE , DELETE task on table.

SAP NetWeaver Gateway Service Builder tools is SAP GUI based modeler to create and publish Odata services using transaction SEGW. SEGW (Service Builder) is the starting transaction which can handle several projects in parallel.

Steps to create Project:

1. Execute transaction code SEGW
   
2. Create Project

3. Describe project name  , description and package.

4.Once you click on local object below screen will appear.

5.Project is created successfully.

Four folders will be created.

1. Data Model
2. Service Implementation
3. Runtime artifacts
4. Service maintenance.

Below are the key parameters present while creating a Data Model/OData Artifacts

• Entity Types
•  Entity Sets
•  Complex Types
•  Associations
•  Association Sets
•  Function Imports

Each entity type can have a so called data dictionary binding to an existing DDIC structure element. The data dictionary binding of entries allows for the reuse of semantics that SAP or the customer has stored in the data dictionary.

There are Properties and Navigation Properties associated with each Entity Type.

• The name of the property is seen in the column “Name” which is visible externally to the OData world.
• In the column “EDM Core Type”, we assign the EDM data type that is behind each property.
• In the column “Label”, we can assign more details descriptions that will help the developer consuming the service to understand the purpose of this property.

Entity Sets are instances of entity types.Through the data dictionary binding of an entity type we will be able to derive:

• A suitable EDM data type
• The length of a data type, as well as
• A proposal for the label.

The Navigation Property is a property which contains a link. The link represents an association instance. The association describes the cardinality between the entity sets.

An Association defines a relation from one collection to another collection. Recursive relations are allowed. Associations allow zero, one or many navigation relations in each of the two directions.

Entity Set is a collection in OData that represents a potentially empty resource of entries. The cardinality is zero to many.

Create Table using SE11 with Two fields.

• Emp_Id
• Name

For Business Users, ease of access has become critical with the advent of various mobile devices that support end-to-end scenarios and also provides a rich user experience. There is a need to better integrate data, reduce complexity and improve productivity. This has been a challenge for the Developer community to be able to support multiple platforms to consume enterprise data more easily than ever before and on the other hand provide solutions that are scalable and with low TCO (Total Cost of Ownership).

Point-to-point solutions are not the right way as it has lot of drawbacks including duplication of development effort, increased cost, complex landscape, poor scalability and difficult to maintain.

SAP NetWeaver Gateway is a technology that has the answer to this. It can seamlessly connect devices, platforms and environments to SAP Enterprise Data using the OData services. SAP NetWeaver Gateway offers connectivity to SAP Business data using any programming language and without the need of strong SAP development knowledge.

SAP NetWeaver Gateway comes with design-time tools to facilitate modeling OData services for consumption. These tools improve user experience and provide automatic connectivity to the SAP backend that reduces development efforts and improves productivity.

SAP NetWeaver Gateway sits on top of the existing SAP Backend infrastructure. There are set of add-on components that needs to be installed on a SAP Backend system to enable SAP NetWeaver Gateway services. It is this architecture that enables consumption of SAP data by variety of interfaces such as BAPIs and RFCs

SAP NetWeaver Gateway Service Builder tools is SAP GUI based modeler to create and publish OData services using transaction SEGW.

There is a lot of data on the web today but lot of it is locked up in different specific applications or formats and different to access from outside. Many Organizations have now started exposing data using REST based services however, it is difficult to write applications which works with multiple data sources as each provider will expose the data in a slightly different way. OData service producer can expose its service along with metadata which contains the semantics for consumption. OData exploits the common formats like XML, Atom and JSON for communication which are commonly understood. Clients can now understand these OData services using generic tools and can combine information from multiple data sources.

Exposing your data with OData services comes with multifold advantages. For example, as we mentioned earlier, as a consumer, you need not worry about the programming language used by producer as long as the services are exposed as OData service.

OData provides the middleware between producers and consumers to communicate data.

It has the ability to engage developers with or without SAP Knowledge within their development tool of choice. It provides rapid development approach along with the Standard and simple service interfaces (REST) and data protocols (OData/ATOM).

The below mentioned points adds focus to the advantages offered-

1. Opening the door for millions of developers to create solutions connecting to SAP

2. Reduce complexity, skill set requirements and deployment barriers

3. Shorten development times/cycles

4. Converting RFCs to OData using Gateway