All things about ABAP Implementation

ABAP is a residual programming language for SAP database, and hence unlike other programming languages, you don't need to create separate file structure for ABAP. In the database, all ABAP programs can be distinguished in two different forms:

Source Code:           This can be viewed and edited with the ABAP workbench tools.
Generated Code:     This is binary representation, to an extent similar to byte code languages such as Java.

ABAP programs execute under the control of the runtime system, which is a part of SAP kernel. This runtime system is responsible for processing ABAP statements, controlling the flow of screens, and responding to events. Sounds similar to the kernel in C, C++, Isn't it? A key component of ABAP runtime system is the Database interface (can be compared to Visual Basic 6.0), which turns database independent ABAP statements (also known as Open SQL) into statements understood by the underlying DBMS. The database interface handles all the communication with the relational database on behalf of ABAP programs; it also contains extra features such as buffering of frequently accessed data in the local memory of the application server.

If you remember from the introduction, SAP was one of the first languages to propose a layered architecture. It has three different layers namely Presentation Layer (GUI), Application Layer (Programs written by developers) and the Database Layer where all the data is stored and retrieved from user driven conditions, commands given by end user programmer through presentation layer.

With this basic knowledge of ABAP, let us dive into the coding heads first. We will visit the important topics as and when they pop up.