ABAP - ADVANCED BUSINESS APPLICATION PROGRAMMING LANGUAGE.
It is 4th generation language and it is a proprietary language of SAP.
ABAP is a programming language for developing applications for the SAP R/3 system. ABAP is one of many application-specific fourth-generation languages (4GLs) first developed in the 1980s. The most basic functions were written in ABAP. ABAP/4 is the language created by SAP AG for implementation and customization of their R/3 system.
The ABAP programming language was originally used by developers to develop the SAP R/3 platform. ABAP was one of the first languages to include the concept of Logical Databases (LDBs), which provides a high level of abstraction from the basic database level.
It was also intended to be used by SAP customers to enhance SAP applications – customers can develop custom reports and interfaces with ABAP programming. The language is fairly easy to learn for programmers but it is not a tool for direct use by non-programmers. Good programming skills, including knowledge of relational database design and preferably also of object-oriented concepts are required to create ABAP programs.
Tool Bars:
1). Menu Bar
2). Standard Tool Bar ( containing command field )
3). Application Tool Bar
4). Status Bar ( containing system information, client number, T-code )
ABAP Language Contains Topics
1.Data Dictionary Objects
Data Base Tables
Views
Data Types
Type Groups
Domains
Search helps
Lock objects
2.Internal Tables
Internal Tables Introduction
Declaring Internal Table
Populating Internal Table
Processing Internal Table
Initializing Internal Tables
3.Moduralization Techniques
Sub-routines
Function Module
4. REPORTS
Classical
Interactive
Abap list viewer (ALV)
5. BDC - Batch Data Communication
Session method
Call Taransaction Method
LSMW
6. Module pool Programming
Screen painter
Menu painter
7. Forms
Scripts
Smartforms
8.Cross-Aplications
ALE & IDOCS
BAPI's
BADI’s
9.Miscellaneous Topics
Correction & Transport request (CTS)
Transport Organizer
Work Bench Request
Task Creation
Release Objects
SAP Memory & ABAP Memory
SD Flow
MM Flow
ABAP Application Server
To perform any processing for a user's request, a work process needs to address two special memory areas: the user context and the program roll area. The user context is a memory area that contains information about the user, and the roll area is a memory area that contains information about the programs execution.
USER Context
A user context is contains information about the user like user name, login id and which program is running currently.
Instance
The term instance means application server
The term central instance means database server
In general the term instance means server.
Roll In
When a job is assigned to a work process it creates pointers to the user context and roll area this process is called Roll In.
Roll Out
After the execution of the job the pointers assigned to both user context and roll area are deleted this process is called Roll Out.
Dialog Steps
This is the time taken by the systems to show the next screen from existing screen is called as dialog step.
Work process
This is the area in which actual work is done.
Types of Work Process
1. Dialog or Online Process- for Dialog request.
2. Update Process- Request to update data in database.
3. Background Process- Background jobs.
4. Spool Process- print spool request.
5. Enque Process – Logical lock requests
6. Message Process- Routes messages between application server with in an R/3 system
7. Gateway Process- Funnels Messages into and out of the R/3 system.
Components of Work Process
Each Work Process is composed of the following
1. A task handler
2. An ABAP/4 Interpreter
3. A screen Interpreter.
4. A Database Interface
All requests pass through the task handler, which then funnels the request to the appropriate part of the work process and the Interpreters Interpret the ABAP/4 code.
Messages
1. S (Success): Green color status bar.
2. E (Error): Red color status bar.
3. W (Warning): Yellow color status bar.
4. I (Information): In a pop-up box.
5. A (Abort): In a pop-up box.
6. X (Exit): Comes out of the program.
