There is no specific syntax for a dangling reference in Oracle PL/SQL, as a dangling reference is an error condition that occurs when a program attempts to access or manipulate an object that no longer exists or has been removed. Dangling references can occur in various ways, such as when a program tries to access a variable that has already been deallocated, or when a program tries to use a cursor that has been closed or invalidated. To avoid dangling references, it's important to properly manage the lifetime of objects and to ensure that all references to objects are properly cleaned up when they are no longer needed. This can be done using techniques such as exception handling and explicit error raising. If a dangling reference does occur in a PL/SQL program, the error message will typically provide information about the nature of the error and the location in the code where the error occurred. This information can be used to diagnose and fix the problem, such as by modifying the code to properly handle the object or reference in question.
Dangling Reference Syntax in Oracle
SELECT column_name_1, <column_name_2>
FROM table_name alias
WHERE object_name IS DANGLING;
Location 1
The SELECT clause for selecting attributes from the object table
Location 2
The FROM clause for specifying the name of the object table
Location 3
The IS DANGLING clause
validation_clauses
{ VALIDATE REF UPDATE
[ SET DANGLING TO NULL ]
| VALIDATE STRUCTURE
[ CASCADE { FAST | COMPLETE } ]
[ into_clause ]
{ OFFLINE| ONLINE }
}