【Oracle】集合（联合数组（索引表），嵌套表，变长数组，记录类型的嵌套表）的初始化与赋值，以及它们的区别
--其中嵌套表与变长数组在赋值之前必须初始化，可以使用与集合类型同名的函数来进行初始化，联合数组无需初始化

--1.联合数组：

DECLARE  TYPE object_rec IS RECORD(    object_id   all_objects_loc.object_id%TYPE,    object_name all_objects_loc.object_name%TYPE,    object_type all_objects_loc.object_type%TYPE);  TYPE object_tab_type IS TABLE OF object_rec;  object_tab object_tab_type;  TYPE obj_cur_type IS REF CURSOR; --声明游标变量类型  obj_cur obj_cur_type;BEGIN  OPEN obj_cur FOR    SELECT a.object_id, a.object_name, a.object_type    FROM   all_objects_loc a    WHERE  rownum <= 10;  FETCH obj_cur BULK COLLECT    INTO object_tab;  CLOSE obj_cur;  FOR i IN 1 .. object_tab.count LOOP    dbms_output.put_line('object_tab(' || i || '):' || object_tab(i)                         .object_id || ',' || object_tab(i).object_name || ',' || object_tab(i)                         .object_type);  END LOOP;END;/