Object references are useful for uniquely identifying and locating an object.
Within Oracle8i, a reference to an object within an object table may be obtained by using the
An object type may be declared as a reference (
REF) to another object type.
When you have completed this module, you will be able to:
Describe the Structured Query Language (SQL) enhancements that allow you to query related object tables
Detect dangling references
Write a query using a
DEREF data type to retrieve related data
Determine when PL/SQL is appropriate or required for querying object tables
Write a PL/SQL block to retrieve data from an object table
In the next lesson, we will begin describing the SQL enhancements that allow you to query related object tables.