All the code used in this chapter can be downloaded from the following GitHub link: https://github.com/PacktPublishing/Mastering-SAP-ABAP/tree/master/Chapter02.

The Data Dictionary is a set of information describing the objects of a database and the relationship between its elements.

The Data Dictionary includes a domain, Types (StRUCTURES, DATA TYPE, and TABLE TYPE), tables, views, search helps, and lock objects.

The following diagram explains the division of objects in a Data Dictionary:

To create an object for the Data Dictionary, we need to use the SE11 transaction. The transaction code is usually only a few characters long and guides you directly to the screen of the task that the user wants to perform. This screen is shown in the following screenshot:

A domain...

In most cases, business processes in the SAP system are based on recorded data. For this purpose, a model based on relational data is used. A database table is, therefore, an object for storing data. It offers many possibilities to support the work of a programmer.

Creating a table is as simple as it is in the other objects of the dictionary. The user starts this process in the SE11 transaction—they select the Database table checkbox and enter a name (which must start with the character Z or Y), as shown in the following screenshot:

Then, they need to click on the Create button. The SAP system will take the user to a screen where they can choose some options. A short description should be entered as it is an obligatory field. The screen the user will see is as follows:

As we can see, there are two fields to fill in at this stage. The first one (Delivery...

After learning about the objects in the Data Dictionary, we can start talking about the syntax declaration in ABAP. The easiest way to declare variables is as follows:

data: lv_first_variable TYPE c. 

Variables are named data objects that are used to store values within the allotted memory area of a program. It is good practice to properly name local variables. It is assumed that the first two characters in the variable name determine its use. The first letter indicates whether the variable is global or local. If the local variable starts with l, then in the case of global variables, g is the first letter. The second character determines what type the object is:

• Variable: v
• Line: s
• Internal table: t

Each variable must have a type that describes what is stored inside. A variable may have the following types:

• Elementary types
• References
• User-defined types...

This chapter described everything you need to know about when you work with the SAP system. It is worth you understanding this chapter because it is the introduction to the modern SAP system. The information in this chapter teaches you about the use of explicit techniques when working with the system dictionary.

The ABAP Dictionary contains information about all the metadata in the SAP system. The ABAP Dictionary is a very important part of the SAP system, and understanding it is necessary for fast and efficient programming. This issue is very extensive and, in most programming cases, you need to use the ABAP Dictionary. 

In the next chapter, we will talk about database access in ABAP.

The following questions will allow you to consolidate the information contained in this chapter:

1. What characters must the names of the objects in the ABAP Dictionary begin with?
2. What is a field symbol?
3. What are the elementary types in the SAP system?