Object Oriented Programming in SAP ABAP

Object oriented programming tries to map the real world objects with their attributes and methods as realistically as possible in program constructs. The aim is to create the program flow in such a way as if it is taking place in the real world. This makes the interaction between the developer and the user easier. The user can formulate business requirements on a program in the language in which the user is familiar with and the developer can convert these directly instead of the classic programming model.

In the object oriented programming model a different approach is used. Attributes and methods which belong to a specific object are grouped together and made accessible to the user using a well defined interface behind which the actual implementation details are hidden. so, the attributes of the object are only changed by the methods of the object and not directly by the user of and object. This ensures that the status of the object is always consistent.

When do you call an object an object oriented programming? if it has these features.

Abstraction
Abstraction refers to the ability to reflect the real world  processes as realistically as possible through programming. These processes can be a business or a technical nature.

Encapsulation
Implementation details are hidden behind well-defined an documented interfaces. They ensure that the abstract representation of a object is used only in accordance with its spefication.

Inheritance
New abstractions i.e. classes are derived from existing ones. They inherit all the attributes and methods of the higher class and can expand and specialize them.

Polymorphism
Different objects can present the same interface to the outside. A user only needs to know the interface and need not know every minute details of the classes.

Collection of Netweaver Certification Questions

ABAP Sample Questions
Database Overview
Netweaver
SAP Web AS Java
Store Management

Document Changes and Change Control

Document change rules can be either user defined or predefined in the system. Only Certain feilds are modifiable once the document changes are posted. Incase of Header: Reference no, Doc Header text are modifiabe only if the posting period is not closed and Incase of Line items: Amount, Posting keys and account number are not modifiable. The others are fixed in IMG.

Conditions for Document field changes:

• Posting Period must be open.
• Line Item is not cleared.
• Line item either debit in customer or credit in vendor.
• Document not a credit memo for Invoice.
• Document not a credit memo for down payment.

Document Change rules can be made in following criteria:

• Account type : A, K, D, M, S
• Transaction class: eg special G.L (down payment)
• Company Code.

An Elementary Search help defines the flow of a standard input help. It is composed of a selection method that defines where to get the data that will make up the hit list, An interface consisting of search help parameters that define the exchange of data between the screen and the selection method and a dialog type that controls how the hit list will be displayed.

A Collective Search help is a combination of several elementary search helps giving the user a different search paths. The interface parameters of the elementary search help are assigned to the parameters of the collective search.

SAP Basis Tutorials covering everything .

Unit 1 Introduction to the R/3 Basis System
Contains Architecture/System landscape, /3 Client/Server Architecture, Instance Concept, Central and Distributed Instances, Work Process Overview, Interaction between Work Processes, Application Services, Data Structure of SAP, Client Concept, System Landscapes, Oracle Directory Structure &  R/3 Directory Structure.

Unit 2 The System Kernel
Contains Principal Architecture of the SAP Web Application Server, WP Multiplexing, Dialog Processing in the SAP System, Communication with the Database, The SAP Transaction, Lock Management in SAP &
Update Processing.

Unit 3 Installation and Setup of SAP R/3
Contains Installation Checks, Preparing for the Installation of SAP ERP Central, Installation of SAP License & Post Installation Steps

Unit 4 & 5 SAP Profiles and Starting and Stopping the R/3 System
Contains Different SAP Profiles, Editing Profiles, Creating New Profile Versions & Imp Profile parameters.

Contains Starting the R/3 System, Stoping R/3 system, Command Prompt Start and Start, Configuring the SAPLOGON, Log and trace, Group Selection & Troubleshoting Startup.

Unit 6 & 7 User Administration & Authorization
Contains Displaying and Creating Users, Copying, Deleting, and Changing Users, Authorization Profile & User Overview SM04.

Contains Types of users, Authorization Concept, Authorization Check, Authorization Objects, Maintaning Authorizations & Role and Profiles.

Unit 8 Operation Modes
Contains The Function of Operation Modes, Redistributing Work Processes for Operation Modes & Checking Operation Mode Changeovers.

Unit 9 Printing in the R/3 System
Contains The Spool Work Process, Creating a New Printer, Changing a Printer, Access Methods in the R/3 System, Spool Request Administration,

Unit 10 Background Jobs
Contains Scheduling Background Jobs, Start Conditions of a Job, Status of a Job, Executing Programs as Job Steps, Checking Background Jobs & Canceling, Changing, and Deleting Background Jobs.

Unit 11 CTS & Transport System
Contains Types of Adaptation, Setting up an R/3 Transport Landscape, Configuring Transport Routes, Transport Process & Performing and Checking Transports.

Unit 12 Client Tools
Contains Creating and deleting a client, Local Client Copy, Remote Client Copy, Transporting a client & Client Change Options

Unit 13 Monitoring
Contains Monitoring Concept and Alert Monitor, Monitoring Architecture Terminology, The Alert Monitor (RZ20), Monitoring: R/3 Servers and Instances, Monitoring: R/3 Users, Monitoring: Workload Analysis, Monitoring: Buffers, Database Monitoring & MONITORING CRITICAL TASKS

Unit 14 Support Packages
Contains Importing Support Packages, Updating the Tools & Importing SAP Notes.

Unit 15 Setting Up Remote Connections
Contains Fundamentals and Types of RFC & Setting Up RFC Connections.

Unit 16 Performance Tuning
Contains Workload statistics, performance monitor & operating system monitor.

Unit 17 SAP Memory Management
Contains Memory Areas, SAP Memory Allocation & Implementation of SAP Extended Memory

Unit 18 SAP Table Buffers
Contains Introduction to Table Buffering in SAP Systems & Analyzing Table Buffering