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ABAP Keyword Documentation →  ABAP - Dictionary →  Classic Objects in ABAP Dictionary →  Data Types →  Structures 

Technical Attributes of Structures

A structure describes a structure type constructed from components and with the following technical attributes:

  • Component name
The name of a component can have a maximum of 30 characters, can contain only letters, numbers, and underscores, and must start with a letter or a namespace prefix. The following restrictions apply:
  • A component name cannot be the name of the pseudo component table_line reserved in ABAP.
  • If a structure is inserted in a database table, however, the component names cannot have any of the reserved names that are not permitted in database tables.
  • Component type
  • For reference-like components, the technical attributes are defined using a reference to a data element that describes a reference type or defined directly in the structure component. When specified directly, data references can be defined by reference to any data type in ABAP Dictionary or to the generic type DATA. Object references can be defined by reference to classes or interfaces in the class library or to the generic type OBJECT,
  • Tabular components are defined by reference to a table type in ABAP Dictionary.
  • Enhancement category
The enhancement category of a structure specifies how a structure can be enhanced using customizing includes or append structures and dictates how ABAP programs that work with data objects of this structure type are checked.
  • Activation type
An activation type can be defined for a structure, like for database tables, but has no specific use here.

Other versions: 7.31 | 7.40 | 7.54


  • In ABAP, the component names of structures are not strictly speaking a technical type attribute. They are listed here however to simplify the picture.

  • The above rules for component names are checked strictly by ABAP Dictionary only for table fields of database tables and not for structures. Component names of structures can contain special characters (such as :) that prevent the component from being addressed in an ABAP program. For this reason, only those component names should be used that comply with the above rules.


Enhancement Category of Structures