Asp.net 使用Oracle9，所以这段代码不适合我，因为Oracle9不理解正则表达式，我正在尝试调整它，但仍然没有得到正确的结果。你能给我一些提示吗？非常感谢。@Walloud抱歉，我看到其他人在使用regexp，并假设您也可以。请参阅更新。小更正：当子项结束时

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使用Oracle9，所以这段代码不适合我，因为Oracle9不理解正则表达式，我正在尝试调整它，但仍然没有得到正确的结果。你能给我一些提示吗？非常感谢。@Walloud抱歉，我看到其他人在使用regexp，并假设您也可以。请参阅更新。小更正：当子项结束时

ID_BOOK | ID_AUTHOR |       NAME AUTHOR       |  Adress        |  Country        |
----------------------------------------------------------------------------------
001     |01         | AuthorU                 | AdrU           | CtryU           |
----------------------------------------------------------------------------------
002     |02*03*04   | AuthorX*AuthorY*AuthorZ | AdrX*NULL*AdrZ | NULL*NULL*CtryZ |
----------------------------------------------------------------------------------

ID_BOOK | ID_AUTHOR |       NAME AUTHOR       | Adress         | Country         |
----------------------------------------------------------------------------------
001     |01         | AuthorU                 | AdrU           | CtryU           |
----------------------------------------------------------------------------------
002     |02         | AuthorX                 | AdrX           | NULL            |
----------------------------------------------------------------------------------
002     |03         | AuthorY                 | NULL           | NULL            |
----------------------------------------------------------------------------------
002     |04         | AuthorZ                 | AdrZ           | CtryZ           |
----------------------------------------------------------------------------------

ID_BOOK | ID_AUTHOR |       NAME AUTHOR       | Adress         | Country         |
----------------------------------------------------------------------------------
001     |01         | AuthorU                 | AdrU           | CtryU           |
----------------------------------------------------------------------------------
002     |02         | AuthorX                 | AdrX           | CtryZ           |
----------------------------------------------------------------------------------
002     |03         | AuthorY                 | AdrZ           | NULL            |
----------------------------------------------------------------------------------
002     |04         | AuthorZ                 | NULL           | NULL            |
----------------------------------------------------------------------------------

SELECT
 ID_Book,
 REGEXP_SUBSTR(ID_Author, '[^*]+', 1, Counter) AS AuthID,
 REGEXP_SUBSTR(Name_Author, '[^*]+', 1, Counter) AS AuthName
FROM Books
CROSS JOIN (
  SELECT LEVEL Counter
    FROM DUAL
    CONNECT BY LEVEL <= (      
      SELECT MAX(REGEXP_COUNT(ID_Author, '[^*]+'))
      FROM Books))
WHERE REGEXP_SUBSTR(Name_Author, '[^*]+', 1, Counter) IS NOT NULL
ORDER BY 1, 2

Author U
Author X*Author Y*Author Z

ID_Book  AuthCount  ID_Author   Name_Author
-------  ---------  ----------  -------------------------
001              1  *01*        *AuthorU*
002              3  *02*03*04*  *AuthorX*AuthorY*AuthorZ*

WITH AuthorInfo AS (
  SELECT
    ID_Book,
    LENGTH(ID_Author) -
        LENGTH(REPLACE(ID_Author, '*')) + 1 AS AuthCount,
    '*' || ID_Author || '*' AS ID_Author,
    '*' || Name_Author || '*' AS Name_Author
  FROM Books
)
SELECT
  ID_Book,
  SUBSTR(ID_Author,
    INSTR(ID_Author, '*', 1, Counter) + 1,
    INSTR(ID_Author, '*', 1, Counter+1) - INSTR(ID_Author, '*', 1, Counter) - 1) AS AuthID,
  SUBSTR(Name_Author,
    INSTR(Name_Author, '*', 1, Counter) + 1,
    INSTR(Name_Author, '*', 1, Counter+1) - INSTR(Name_Author, '*', 1, Counter) - 1) AS AuthName
FROM AuthorInfo
CROSS JOIN (
  SELECT LEVEL Counter
    FROM DUAL
    CONNECT BY LEVEL <= (SELECT MAX(AuthCount) FROM AuthorInfo))
WHERE AuthCount >= Counter
ORDER BY ID_Book, Counter

select b.id_book, a.id_author, a.NameAuthor
from books b left outer join
     authors a
     on '*'||NameAuthor||'*' like '%*||a.author||'*%'

with data (id_book, id_author, name, item_author, item_name, i)
 as (select id_book, id_author, name,
            regexp_substr(id_author, '[^\*]+', 1, 1) item_author, 
            regexp_substr(name, '[^\*]+', 1, 1) item_name,
            2 i 
       from books
     union all
     select id_book, id_author, name,
            regexp_substr(id_author, '[^\*]+', 1, i) item_author, 
            regexp_substr(name, '[^\*]+', 1, i) item_name, 
            i+1
       from data
      where regexp_substr(id_author, '[^\*]+', 1, i) is not null)
select id_book, item_author, item_name
  from data;

SELECT distinct id_book,
     , trim(regexp_substr(id_author, '[^*]+', 1, LEVEL)) id_author
     , trim(regexp_substr(author_name, '[^*]+', 1, LEVEL)) author_name
 FROM yourtable
CONNECT BY LEVEL <= regexp_count(id_author, '[^*]+')
ORDER BY id_book, id_author
/

ID_BOOK    ID_AUTHOR    AUTHOR_NAME
------------------------------------
001        01           AuthorU
002        02           AuthorX
002        03           AuthorY
002        04           AuthorZ
003        123          Jane Austen
003        456          David Foster Wallace
003        789          Richard Wright

SELECT str, SUBSTR(str, substr_start_pos, substr_end_pos) final_str
  FROM
 (
  SELECT str, substr_start_pos
       , (CASE WHEN substr_end_pos <= 0 THEN (Instr(str, '*', 1)-1) 
            ELSE substr_end_pos END) substr_end_pos
    FROM
   (
   SELECT distinct '02*03*04' AS str
       , (Instr('02*03*04', '*', LEVEL)+1) substr_start_pos
       , (Instr('02*03*04', '*', LEVEL)-1) substr_end_pos           
    FROM dual
   CONNECT BY LEVEL <= length('02*03*04')
   )
  ORDER BY substr_start_pos
  )
 /

STR         FINAL_STR
---------------------
02*03*04    02
02*03*04    03
02*03*04    04