nested table syntex in oracle
-- can be stored in database
DECLARE
TYPE customer_type IS TABLE OF VARCHAR(20);
customer_table customer_type := customer_type(); -- initialization of collection
v_indx NUMBER
BEGIN
customer_table.EXTEND(4); -- you have to do this for using the table
customer_table(1) := 'MIKE';
customer_table(2) := 'MIKE';
customer_table(3) := 'MIKE';
customer_table(4) := 'MIKE';
customer_table(4) := 'MIKE'; -- Should be in sequence throws error
customer_table.DELETE(3); -- delete third item
v_indx := customer_table.FIRST; -- returns first index (customer_table.LAST - returns last index)
-- traversing using while loop
WHILE v_indx IS NOT NULL
LOOP
dbms_output.put_line(customer_table(v_indx));
v_indx := customer_table.NEXT(v_indx);
END LOOP display_loop;
END;
/