In ABAP Dictionary we can define following basic types.
- Data Element
- Structure
- Table Type
We can use these data types to define data objects in ABAP programs.
Data Elements use domains or predefined DDIC types to define their technical attributes.
A structure consists of components that can be elementary fields or a structure or a table.
The line type of a table type can be a structured type or an elementary type.
Data Elements
Data Elements combine the technical information about the data type with semantic information.
Data type tab
SAP recommends using domains to specify the technical type of a data element. However, you can also define the data element using the same the same integrated types that are used to define the domains.
Field Labels tab
The semantic information is maintained in the field labels. The field labels (short, medium, long) can be displayed on screens or selection screens to explain the field content.
Fields labels can be translated into other languages for to support multi language. Search help can be appended to a data element.
Data Elements Additional options Documentation, Search help, Set/Get Parameter, Default component name, Change document, Input history.
Steps to create Data Elements
Structures
We can define a simple as well as nested structure in the ABAP Dictionary. A structure comprises of components which could refer to a data element, or integrated types, or table types, or Definition of database tables and database views, or other structure types.
If a component refers to a table type, it creates a deep structure.
The simplest form of a structure is a list of fields typed with data elements. This form of a structure is called a flat structure.
Nested structure is created when a component refers to another structured object.
Steps to Create Simple and Nested Structure
Table Types
Define table types using an existing dictionary type. Database tables, structure definitions, views, data elements, direct type definitions, or existing table types can be used as line type.
In an ABAP program, data objects referring a table type creates a two-dimensional array known as internal tables.
Steps to create Table Type.
Deep Structures
A deep structure is created when a component of structure refers to ta table type.
Steps to create Deep Structure.