ABAP Keyword Documentation → ABAP − Reference → Processing Internal Data
Meshes
Meshes are instances of the following defined mesh types:
...
TYPES snode ... ASSOCIATION _assoc
TO tnode ON tcomp1 = scomp1 [AND ...].
...
TYPES END OF MESH
These are special structures whose components (referred to as nodes) are either structured internal tables or reference variables that point to structured internal tables.
The addition ASSOCIATION makes it possible to define
mesh associations
(using ON conditions) between start nodes and target nodes of the mesh. These
semantic relationships between the mesh nodes can be evaluated in mesh paths. The mesh paths can be used in expressions and processing statements for meshes.
Other versions:
7.31 | 7.40 | 7.54
Notes
- A mesh node is addressed in the same way as a normal structure component; by using the structure component selector
(
-) or the object component selector (->). The mesh associations are evaluated in mesh paths. If no path is specified, the mesh node is handled in the same way as a normal structure component. The same applies to field symbols or reference variables that point to mesh nodes. The statementMOVE-CORRESPONDINGalso handles a mesh like a normal structure.
- In a simple case, the relationships (implemented using mesh associations) between mesh nodes can be compared to foreign key dependencies. Here the start node of a mesh association is the check table and the target node is the foreign key table. The use of mesh paths makes it easier to evaluate these relationships, without the need to program the relevant selections.
Example
The program DEMO_MESH_PACK demonstrates an application based on meshes, which analyses the repository objects in packages. All the possible uses of meshes are demonstrated and can be precisely analyzed in the debugger.