ZPRAC_CDS_010.txt

/*
Table Function:

    Important things:
       1. Parameters are optional
       2. Return Paramets is present(Workarea, Internal Table)
       3. Need class(Public) & methods(Static)
       4. Interface: IF_AMDP_MARKER_HDB is needed

N.B: As this is not going to used in ABAP programs so, there is no extra annotations.
*/
@EndUserText.label: 'Practice Table Function 001 - Simple'
define table function ZPRAC_TF_001
returns
{
  Client : abap.clnt;
  Travel_ID : /dmo/travel_id;
}
/* Method Calling  */
implemented by method
  ZCL_PRAC_TF_001=>get_travel_id;
/*
------------------------------------------------------------------------------------
Class: zcl_prac_tf_001
*/
CLASS zcl_prac_tf_001 DEFINITION PUBLIC.

  PUBLIC SECTION.
    INTERFACES: if_amdp_marker_hdb.
    CLASS-METHODS: get_travel_id FOR TABLE FUNCTION ZPRAC_TF_001.
  PROTECTED SECTION.
  PRIVATE SECTION.
ENDCLASS.

CLASS zcl_prac_tf_001 IMPLEMENTATION.

  METHOD get_travel_id BY DATABASE FUNCTION FOR HDB LANGUAGE SQLSCRIPT OPTIONS READ-ONLY USING zprac_cds_001.
    RETURN SELECT Client_Name AS Client, TravelId AS Travel_ID FROM zprac_cds_001;
  ENDMETHOD.

ENDCLASS.
/*
------------------------------------------------------------------------------------
CDS View: ZPRAC_CDS_010
*/
/* 
Calling of table function in a CDS View 
    1. Multiple CDS Views can be created on a table function.
    2. Inner, Left Outer, Right Outer Join can be done on table functions.
*/
@AbapCatalog.sqlViewName: 'ZPRAC_SQL_010'
@AbapCatalog.compiler.compareFilter: true
@AbapCatalog.preserveKey: true
@AccessControl.authorizationCheck: #CHECK
@EndUserText.label: 'Practice CDS View 010 - Table Function'
define view ZPRAC_CDS_010
  as select from ZPRAC_TF_001
{
  Travel_ID
}