SDB_RLEV - Data reference level

Enumarators overview

• RL_1 (1) - Pointer reference
  
• RL_2 (2) - Pointer to pointer
  
• RL_3 (3) - Level 3 pointer
  
• RL_direct (0) - Direct reference
  
• RL_generic (-2) - Generic attributes
  
• RL_reference (-1) - Reference property
  
• RL_undefined (-99) - Undefined reference level
  

Enumerator details

1. RL_undefined - Undefined reference level
   Code: -99
   to list
2. RL_generic - Generic attributes
   

   The reference type generic allows defining generic attributes.

   The dimension of a generic attribute allows limiting the number of possible representations to the defined dimension value.

   Notes:

   Die Dimension fuer generische Felder kann begrenzt werden, darf aber nicht 1 sein (wird geämdert nach undefiniert). Diese Einschränkung wird in weiteren ODABA2-Versionen aufgehoben.

   Code: -2
   to list
3. RL_reference - Reference property
   

   Reference is the default type for references and relationships in persistent structures. References are usually considered as collection references, regardless whether they refer to one or more instances.

   Using reference type "reference" for attributes is allowed only in transient structures or in transient members of persistent structures. In this case it is considered as reference field according to the C++ conventions.

   Notes:

   Shared base structures, however, which are references from a technical perspective, are not mrked as reference properties.

   Code: -1
   to list
4. RL_direct - Direct reference
   

   The typical way of referring to an instance is the direct reference. In a sense, direct references are always local references. Referring to a property directly within a structured instance means, the property belongs to the instance or is owned by the instance. Directly referenced variables usually require the maximum space defined for the variable.

   In a program, directly referenced variables are usually local variables.

   Code: 0
   to list
5. RL_1 - Pointer reference
   

   A pointer references points directly to an instance in the main storage (internal memory). It can be defined as transient members or in transient structures.

   Code: 1
   to list
6. RL_2 - Pointer to pointer
   

   A pointer to pointer references point to a pointer, which points to an instance in the main storage (internal memory). It can be defined as transient members or in transient structures.

   Level 2 pointers are typically passed as return parameters for pointers

   Code: 2
   to list
7. RL_3 - Level 3 pointer
   

   Level 3 pointers are rarely used and point to a level 2 pointer, which points to a pointer that points to an instance in main storage. It can be defined as transient members or in transient structures.

   Code: 3
   to list