如何在oracle中为记录类型编写循环

Question

我有以下声明在我的包中编译好:

包头:

   TYPE role_user_type IS RECORD (
      ROLE_ID        some_table.ROLE_ID%TYPE,
      SUBGROUP       some_table.USER_ID%TYPE
   );

身体:

ROLE_USER_REC                  MY_PACKAGE.ROLE_USER_TYPE;

SELECT B.USER_ID, B.ROLE INTO ROLE_USER_REC
FROM some_table where user_id like 'M%'

循环的骨架是什么ROLE_USER_REC？我们甚至可以通过它吗？

Answer 1

没有什么可循环的.

role_user_type 定义单个记录,您可以通过以下方式访问:

dbms_output.put_line( role_user_rec.role_id || ', ' || role_user_rec.subgroup );

SELECT ... INTO只要返回多行,您的操作就会失败.

如果需要存储其中几条记录,可以使用嵌套表,如
TYPE role_user_tab IS TABLE OF role_user_type:

示例:

DECLARE
  TYPE role_user_type IS RECORD (
     ROLE_ID        VARCHAR2(10),
     SUBGROUP       VARCHAR2(10)
  );
  TYPE role_user_tab IS TABLE OF role_user_type;
  role_user_rec role_user_tab;
BEGIN
  SELECT 'A', 'B'
  BULK COLLECT INTO role_user_rec
  FROM dual;
  FOR i IN role_user_rec.FIRST .. role_user_rec.LAST LOOP
    dbms_output.put_line( role_user_rec(i).role_id || ', ' || role_user_rec(i).subgroup );
  END LOOP;
END;

Answer 2

您可以使用游标FOR循环:

BEGIN
  FOR role_user_type IN ('SELECT B.USER_ID, B.ROLE FROM some_table where user_id like ''M%'')
  LOOP
    dbms_output.put_line('User ID: '||role_user_type.user_id);
    etc...
  END LOOP;
END;

另一种选择:

DECLARE
  CURSOR C IS
SELECT B.USER_ID, B.ROLE 
  FROM some_table 
 where user_id like 'M%';
BEGIN
  FOR role_user_type IN C LOOP
    dbms_output.put_line('User ID: '||role_user_type.user_id);
    etc...
  END LOOP;
END;