Step 2

We would however prefer to process this HANA artefact in an ABAP step in our BW process chain(s). For this purpose we create aHANA  procedure that can be called via SAP ABAP class.

PROCEDURE "BIANALYST"."BIA_DEMO.HANA::BIA_PROC_BY_ABAP_PC" ( IN DEL_TAB nvarchar(1), IN SOURCE NVARCHAR (10) )
    LANGUAGE SQLSCRIPT
    SQL SECURITY DEFINER
    DEFAULT SCHEMA "BIANALYST"
    AS
BEGIN
--BEGIN AUTONOMOUS TRANSACTION could be used to trigger asynchronous mode
-- Use such approach to call and do whatever you like in HANA
--This Procedure will be called by SAP-BW Process Chain ABAP Report
  if DEL_TAB = 'X' THEN
    if source = 'TRFN' then
    --drop all data in TRFN table  (HANA table) that will be uploaded by Process Chain in ABAP BW but HANA functionality:)
                --delete from BIANALYST.BIA_TRFN_DATA;
        call "BIANALYST"."BIA_DEMO.HANA::BIA_LOAD_TRFN_DATA";
        ELSEIF source = 'QUERY'    then
        ELSEIF source = 'ABAP'     then
        ELSEIF source = 'HANA'     then
        ELSEIF source = 'AMDP'     then
        ELSEIF source = 'INFOPROV' then
     END IF ;
   END IF;
END

Additionally, all flow graphs are generating Stored Procedures (SP) which can also call directly from ABAP classes.

In our case, I created a procedure to combine several loads in a single Stored Procedure with all its tasks to have less objects and use parameters to trigger the individual load.

My procedure therefore has Input parameters to set up the specific task from the outside world.

Step 3

Now we are set from a HANA point of view.

What is missing is a way to start the procedure by ABAP report. This can be achieved by defining an ABAP class using a HANA method.

CLASS zcl_bia_abap_call_hana DEFINITION
  PUBLIC
  FINAL
  CREATE PUBLIC .
PUBLIC SECTION.
  INTERFACES if_amdp_marker_hdb.

CLASS-METHODS GET_BIA_HANA_DATA
  importing  value(IN_DEL) type  rs_bool
             value(IN_SOURCE) type CHAR10
  exporting  value(OUT_STR) type string.

  PROTECTED SECTION.
  PRIVATE SECTION.
ENDCLASS.

CLASS zcl_bia_abap_call_hana IMPLEMENTATION.

METHOD GET_BIA_HANA_DATA by database procedure
                         for hdb language sqlscript.
  DECLARE LV_INFO NVARCHAR(100);
  DECLARE EXIT HANDLER FOR SQLEXCEPTION
BEGIN
  lt_error = SELECT ::SQL_ERROR_CODE as "SQL Fehler",
             ::SQL_ERROR_MESSAGE as "Info" FROM PUBLIC.DUMMY;
  --In case of errors=> Send Info back to ABAP

   select "Info"  INTO OUT_STR  from :lt_error ;
END;

--CAll the HANA Procedure / Flowgraphs or whatsoever to fullfill its HANA tasks :)
  call "BIANALYST"."BIA_DEMO.HANA::BIA_PROC_BY_ABAP_PC"(:IN_DEL,:IN_SOURCE ) ;
ENDMETHOD.

My Class is using the two-input parameter, which are being used in my stored procedure in HANA as well.

CLASS-METHODS GET_BIA_HANA_DATA
  IMPORTING  VALUE(IN_DEL)    TYPE rs_bool
             VALUE(IN_SOURCE) TYPE CHAR10
  EXPORTING  VALUE(OUT_STR)   TYPE string.

Additionally, we have a third parameter OUT_STR we will use to return any problems occurring from the HANA point of view (e.g., SQL errors, Authorization problems etc.).

The next step is optional, but I think that it is valuable for your monitoring to spot and evaluate possible errors.

I am using the simple variant by passing a string only to the process chain.

For more details, how to define specific SQL exit handlers, see SAP Online help

https://help.sap.com/viewer/de2486ee947e43e684d39702027f8a94/2.0.04/en-US/ebc8b804be2e44789d767895f32503cf.html

To receive such errors, we have to declare an error message handler as shown below and past e.g., the Info back to the ABAP calling class.

METHOD GET_BIA_HANA_DATA by database procedure

for hdb language sqlscript.

DECLARE LV_INFO NVARCHAR(100);
DECLARE EXIT HANDLER FOR SQLEXCEPTION
  BEGIN
    lt_error = SELECT :: SQL_ERROR_CODE as "SQL Fehler",
                      :: SQL_ERROR_MESSAGE as "Info" FROM PUBLIC.DUMMY;
-- In case of erros=> Send Info Back to ABAP

    SELECT "Info" INTO OUT_STR FROM :lt_error;
  END;

As you can see in upper code example, my error handler is looking for SQL exceptions and storing (if occurred) thus values in internal table “lt_error”.

In my example, I am just returning the error message I called “Info” to my output parameter as string.

This is just a simple way to evaluate on ABAP side, whether an error occurred (string is empty, or not).

Step 4

We can now complete our process chain by including an ABAP step to run the report. The ABAP step triggers the HANA object and evaluates any possible SQL problems that may occur.