The Oracle COLLECT function enables aggregating data into a collection, retaining multiple records within a single row (like a nested table). Essentially, COLLECT takes a column of any type and creates a nested table of the input type out of the rows selected.
A key benefit of this function is that it makes "string aggregation" very simple. One important difference between COLLECT and BULK COLLECT is that it cannot be used with local PL/SQL types, since a SQL type is needed.
CREATE TYPE phone_book_t AS TABLE OF phone_list_typ;
SELECT CAST(COLLECT(phone_numbers) AS phone_book_t)
H FROM customers;
Related Code Snippets:
- BULK COLLECT - The SQL engine will bulk bind all the values present for a \column in a table befor...