What is Append Structure?
An append structure is a structure in the ABAP Dictionary appended to another structure or database table that adds its components to this structure or table.
What is Include Structure?
Include structures are the components that can be defined by including the components of other structures in the ABAP Dictionary, like database tables, or views.
Append Structure vs Include Structure
Append structure is used to append the structure to the standard table whereas Include structure is used to include the structure to the custom table.
The same Append structure cannot be appended in more than one standard database table. The same include structure can be included in any no of custom tables.
Key Differences Between Append Structure and Include Structure
- Purpose: Append structures extend existing objects, while including structures group reusable components.
- Attachment: Append structures are attached to a single object, while included structures can be referenced by many.
- Modification: Changes to an include structure affect all referencing objects, while changes to an append structure only affect the attached object.
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There are three types of Adding Fields
1. Normal structures (WHICH ARE NOTHING BUT INCLUDE STRUCTURES THAT START WITH ".INCLUDE)
2. APPEND STRUCTURES (FOR STANDARD TABLES) (START WITH ".APPEND")
3. Customizing includes(FOR STANDARD TABLES) (".CI", THESE ARE DONE BY END USERS NOT BY US ).
STRUCTURE IS A COLLECTION OF FIELDS.
Coming to the difference between INCLUDE Structures and APPEND Structures.
INCLUDE STRUCTURES CAN USED BY US TO ADD FIELDS INTO ANY ZTABLES. BECAUSE, IN A ZTABLE, WE CAN ADD FIELDS WHEREVER WE WANT.
APPEND STRUCTURES ARE USED ONLY TO ENHANCE STANDARD TABLES. STANDARD TABLES MAY HAVE INCLUDE STRUCTURES ALREADY CREATED , BUT IF WE WANT TO ADD SOME MORE FIELDS TO THE STANDARD TABLES, WE NEED TO GO FOR APPEND STRUCTURES.
APPEND STRUCTURES SHOULD BE ADDED AT THE END OF A STANDARD TABLE. THIS IS A MUST. BECAUSE WE SHOULD NOT CHANGE THE ORIGINAL STANDARD TABLE IN THE MIDDLE.
SOME STANDARD TABLES FOR WHICH THERE ARE LONG DATA TYPE FIELDS cannot be enhanced because, LONG TYPE FIELDS SHOULD ALWAYS BE AT THE END AND APPEND STRUCTURES SHOULD ALSO BE AT THE END, SO THERE WILL BE A CONFLICT.
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