Simple and Nested structures

A structure consists of components in the following forms:

• Data elements
• Integrated types
• Table types
• Definition of database tables and database views
• Other structure types

When the fields of an actual two-dimensional object are integrated in a structure by including a view or DB tables, the data object that can be generated from this structure remains flat and is one-dimensional.

A deep structure is always created when you use a table type to define a component. Although this component is then two-dimensional, the other components in the structure remain flat (one-dimensional).

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. A data object based on this structure type is always one-dimensional (as opposed to table-like, two-dimensional data objects). You address the individual elements (components) of the structure using the name of the structure, a hyphen, and the name of the components.​

You can include another structured object in the structure and assign it to a component. The component refers to the structured object and the new data object is described as a nested structure.

When a structure is included as an include structure, it can be assigned a name of a group. In ABAP programs, the name of a group is an additional addressing option for data objects declared with reference to the structure. All components of the included structure can be addressed together using this name or individual components can be addressed using the structure component selector (-) after the name.