Constants must be immediately initialized at declaration. They cannot be reassigned any value after the declaration, as they are constant. This rule prevents PLS-00322 exceptions from being raised at runtime.

The following code snippet illustrates this rule:


== Noncompliant Code Example

----
DECLARE
  foo CONSTANT PLS_INTEGER NULL; -- Noncompliant PLS-00322
  bar CONSTANT PLS_INTEGER NOT NULL; -- Noncompliant PLS-00322
  aa CONSTANT PLS_INTEGER; -- Noncompliant
BEGIN
  NULL;
END;
/
----


== Compliant Solution

----
DECLARE
  foo CONSTANT PLS_INTEGER NULL :=42;
  bar CONSTANT PLS_INTEGER NOT NULL := 42;
  aa CONSTANT PLS_INTEGER := 42; -- Compliant
BEGIN
  NULL;
END;
/
----

