ABAP Keyword Documentation → ABAP Overview → ABAP and Unicode → Differences between Unicode and Non-Unicode Programs
Structure Enhancements and Unicode Programs
ABAP Dictionary structures and database tables that are delivered by SAP can be enhanced using customizing includes or append structures. These types of changes cause problems in Unicode programs if the enhancements change the Unicode fragment view.
For this reason, the option to classify structures and database tables was introduced, which makes it possible to recognize and handle problems related to structure enhancements. This classification is used during in the program check to create a warning at all points where the program works with structures, and where later structure enhancements can cause syntax errors or changes in program behavior. When you define a structure or a database table in ABAP Dictionary, you can specify the enhancement categories that are displayed in the following table as classification.
| Level | Category | Meaning |
|---|---|---|
| 1 | Unclassified | The structure does not have an enhancement category. |
| 2 | Cannot be enhanced | The structure must not be enhanced. |
| 3 | Can be enhanced and character-like | All structure components and their enhancements must be character-like and flat. |
| 4 | Can be enhanced and character-like or numeric | All structure components and their enhancements must be flat. |
| 5 | Can be enhanced in any way | All structure components and their enhancements can have any data type. |
The warnings displayed after the program check are classified into three levels from the following table, depending on the consequences of the permitted structure enhacements.
| Level | Type of Check | Meaning |
|---|---|---|
| A | Syntax check | An enhancement that fully utilizes the enhancement category of the structure in question leads to a syntax error. |
| B | Extended check | Permitted enhancements can lead to a syntax errors, but not always. |
| C | Extended check | Permitted enhancements cannot lead to syntax errors, although changes to program behavior do result in semantic problems. |
Other versions:
7.31 | 7.40 | 7.54
Example
If the structure ddic_struc in ABAP Dictionary is defined only with
flat components but is classified
as Can be enhanced in any way, then the following program section leads to a warning in the syntax check. If the structure were to be enhanced by a
deep component after the program
was delivered, the program would be syntactically incorrect and no longer executable. This is why in
this case you either have to classify the structure ddic_struc in ABAP Dictionary
as Can be enhanced and character-like or else you cannot specify the offset/length in the program.
str TYPE string,
off TYPE i,
len TYPE i.
...
str = my_struc+off(len).