SetReference

SetReference(zugriffsAusdruck), SetReference(zugriffsAusdruck, backRef), SetReference(STACK, STACK)

Parameter:  Access Path, back reference name.

Attention!
outdated, please use link

After the operation, the pointer p, which is accessed via access path coming from the target object  access path, shall point at the stack top 1 object. If the pointer, that has been selected in the target object, is declared as a 1-1- or 1-m reference in the DDI, it requires to indicate a back reference name as the second operand.

If p != ZERO (before the operation), the currently valid back reference will be caused at first. Then, p and the (new) back reference (pointer or collection) will be set. SetReference is controlled by DDI entries and is cancelled with an error, when trying to generate a reference, which does not comply with the DDI definitions. This is the case, 

• in case the object data type does not match the entered reference data type (the object is no instance of the DDI classes or its derivations)
• in case the object o containing the pointer p does not match the back reference data type in the DDI (object o is no instance of the class entered as a back reference  type in the DDI or of any derived class)
• in case the reference from operation start conflicts with the DDI in reference to reference and back reference
• in case a 1-1 relation back reference does not point at the object o
• in case in a 1-m relation, the object o is no back reference collection element.

A persistent object shall never reference a transient object. This refers to reference and back reference. The following references are allowed:

A transient object can reference a persistent one, if

• the pointer is a dynamic data field and
• of the type POINTER (REL_11 or REL_1M would force a back reference from the persistent to the transient object,. This is forbidden.)
  

Information:  Whenever a persistent object takes part in this operation, a transaction will start.