COLLECT takes as its argument a column of any type and creates a nested table of the input type out of the rows selected. To get the results of this function you must use it within a
column is itself a collection, then the output of
COLLECT is a nested table of collections.
The following example creates a nested table from the varray column of phone numbers in the sample table
CREATE TYPE phone_book_t AS TABLE OF phone_list_typ; / SELECT CAST(COLLECT(phone_numbers) AS phone_book_t) FROM customers;