The CDS view name is the ABAP-level name used within the ABAP environment. It’s the name you use to reference the CDS view in ABAP programs, in other CDS views, or in tools like ADT (Eclipse). It represents the semantic model and is part of the ABAP repository.

On the other hand, @AbapCatalog.sqlViewName defines the technical name of the SQL view that gets created in the underlying database when you activate the CDS view. This SQL view acts as a bridge between the ABAP dictionary and the actual database. The SQL view is stored in the database and can be accessed using standard SQL statements if needed.

In simple terms:

• The CDS view name = used in the ABAP layer (semantic name for CDS).

• The sqlViewName = used in the database layer (technical name for DB view).

For example:

@AbapCatalog.sqlViewName: ‘ZEMP_SQL’
@EndUserText.label: ‘Employee CDS View’
define view ZCDS_Employee as select from zemployee {
key emp_id,
emp_name,
emp_dept
}

Here, ZCDS_Employee is the CDS view name (used in ABAP), while ZEMP_SQL is the SQL view name (created in the database).

Key Differences Summary

DCLs are written using the DEFINE ROLE syntax and stored as authorization objects in the ABAP Dictionary.
They work in combination with authorization checks performed automatically at runtime by the ABAP system — when the CDS view is queried through ABAP, OData, or analytical tools.

Purpose of DCL

• To control access to data at the CDS view level (not in ABAP code).

• To ensure data security and compliance with organizational policies.

• To centralize authorization logic so it’s reusable and not hardcoded in multiple reports or services.

In simple terms:

DCL defines who can access what data in a CDS view.

How DCL Works

1. A CDS view is defined with an authorization check annotation:

   @AccessControl.authorizationCheck: #CHECK
   define view ZCDS_Employee as select from zemployee { … }

   2. A DCL (authorization rule) is created using DEFINE ROLE.

   It specifies the conditions under which a user can access the data At runtime, when a user executes the CDS view (via report, OData, or Fiori app),
   the system automatically filters data according to the DCL rule.

PFCG Authorization Object Link

The function aspect pfcg_auth('AUTH_OBJECT', 'FIELD') links the DCL to a PFCG (Profile Generator) authorization object.
This ensures integration between CDS-level security and SAP’s standard role-based security.

Example authorization object definition:

• Authorization object: ZEMP_AUTH_OBJ

• Field: DEPT

• Values assigned in user role (e.g., user only has DEPT = ‘HR’)

Then when user runs the view:

• They will only see rows where department = 'HR'.

custom Entity:

@EndUserText.label: ‘template Download’

@ObjectModel: {

query: {

implementedBy: ‘ABAP: ZCL_DOWN_TEMPLATE’

}

}

define root custom entity ZCHM__TMP_DWN

{

key docnum : abap.char(10);

comp_code : abap.char(4);

sales_org : abap.char(4);

distr_chn : abap.char(2);

division : abap.char(2);

ref_doc : abap.char(20);

currency : abap.char(8);

ref_item : abap.char(10);

material : abap.char(40);

matl_group : abap.char(9);

net_amount : abap.char(40);

gross : abap.char(15);

quantity : abap.char(13);

price_unit : abap.char(5);

bill_unit : abap.char(3);

file_content : abap.string( 999999999 );

}

then Create a Class where you can write you logic to create the template and pass the file content to the front end.

Now activate the class and expose it the service definition and at last create a web API v4 and pass the URL to the front person to fetch and download the excel sheet.

• ABAP’s database-independent SQL.
• Works on all supported DBs (HANA, Oracle, MSSQL, DB2, …).
• ABAP converts Open SQL statements into the database-specific SQL automatically.
• Ensures portability → same ABAP program runs regardless of underlying DB.
• Supports buffering (e.g., table buffers in SAP).

• Only a subset of SQL is allowed (the part SAP makes portable).

Example :

DATA: it_mara TYPE TABLE OF mara.

SELECT matnr mtart FROM mara
INTO TABLE it_mara
WHERE mtart = ‘FERT’.

• This works in any DB under SAP (Oracle, HANA, DB2, etc.).

• Optimized by SAP kernel, can use table buffering.

2. Native SQL

• Database-specific SQL.

• You write SQL directly for the underlying DBMS.

• Executed via EXEC SQL … ENDEXEC or ADBC (ABAP Database Connectivity).

• No automatic portability → may not work if you change DB.

• No table buffering → always hits the DB.

• Useful when:

  • You need features not available in Open SQL (e.g., DB-specific functions, hints).

  • You want DB-level optimizations.

Example:

DATA: lv_matnr TYPE mara-matnr.

EXEC SQL.
SELECT MATNR INTO :lv_matnr
FROM MARA
WHERE MTART = ‘FERT’
ENDEXEC.

This will only work if the DB syntax matches your system (e.g., Oracle-specific SQL won’t run on HANA).

Key Difference Summary:

Steps to Create Search help Using CDS View.

Step1 : create a CDS view

Step 2 : GOTO SE11 –> Search Help In selection method add the CDS view SQL view name.

Step 3 : Append it in the collective search Refer to the Append structure to add the elementary search in collective.

Test:

Step 4 : In the collective search after append the structure we can call it in the program

We have successfully created A search Help using CDS View.

There are different layers in RAP:

• Interface View (I_)
• Consumption/Projection View (C_ or ZC_)
• Data Definition View (Z_)

Usually, you extend interface or projection views.

Use the EXTEND VIEW Statement

You can extend a CDS view using the EXTEND VIEW ABAP statement.

extend view ZI_YOUR_ORIGINAL_VIEW with ZI_YOUR_VIEW_EXTENSION {
key YOUR_FIELD_1,
YOUR_FIELD_2
}

ZI_YOUR_ORIGINAL_VIEW is the CDS view you’re extending.
YOUR_FIELD_1, YOUR_FIELD_2 must be available in the underlying base table/view or added via association.

An exposed association is one that is defined in a CDS view and is made available (exposed) to consumers of the view — such as other CDS views, analytical queries, or OData services. You define the association using the association […] to clause and then expose it using an alias (typically starting with an underscore _) in the SELECT list.

define view ZI_SalesOrder as select from ZSalesOrderHeader
{
    key SalesOrderID,
    CustomerID,

    association [0..1] to ZI_Customer as _Customer 
        on _Customer.CustomerID = ZSalesOrderHeader.CustomerID

    // Exposing the association
    _Customer
} 

define view ZI_SalesOrder as select from ZSalesOrderHeader
{
    key SalesOrderID,
    _Customer.Name    // Ad-hoc usage of the association
}