Use of Other Built-in Methods for
In addition to the constructor type Oracle also
provides collection methods for use with VARRAYS and NESTED TABLEs.
These methods cannot be used outside of PL/SQL. Collection methods
cannot be used in DML but only in procedural statements.
EXISTS -- Used to determine if a specific
element in a collection exists. EXISTS is used with nested tables
COUNT -- Returns the number of elements that a
collection currently contains not including null values. For varrays,
count is equal to LAST. For nested tables, COUNT and LAST may be
different due to deleted values in interstitial data sites in the
LIMIT -- Used for VARRAYS to determine the
maximum number of values allowed. If LIMIT is used on a nested table
it will return a null.