Reg: Querying Nested table.

Question

Hi,
I am facing a problem with querying the Nested table.
I have created a type
CREATE OR REPLACE TYPE TY_BOOKS OBJECT(           VC_BOOK_NAME VARCHAR2(64)          );
CREATE OR REPLACE TYPE NT_TY_BOOKS AS TABLE OF TY_BOOKS;
I have used this nested table in a table Student.
CREATE TABLE STUDENT
( SID NUMBER(10),
CL_NT_BOOKS NT_TY_BOOKS)
NESTED TABLE CL_NT_BOOKS STORE AS CL_NT_BOOKS_TAB;
The problem is one student can have more than one book. So if I need to select the students who have 'Science' books, i wrote this query.
SELECT S.SID,B.VC_BOOK_NAME FROM STUDENT S, TABLE(CL_NT_BOOKS) B WHERE B.VC_BOOK_NAME='Science';
suppose in the table
SID BOOK_NAME
1000          CL_NT_BOOKS('Science')
1001          CL_NT_BOOKS('Maths'),CL_NT_BOOKS('Science')
This query will return only those student-ids who have only "Science" book not those student-ids who have "Maths" & "Science" books.
RESULT
1000          Science
but not 1001....
Please can any one send me the select query which can select iteratively for books names which contains more than one value.

Answer 1

Hmm, mysterious. It works for me on my 9.2.0.6 dB...
SQL> CREATE OR REPLACE TYPE TY_BOOKS AS  OBJECT( VC_BOOK_NAME VARCHAR2(64) );
  2  /
Type created.
SQL> CREATE OR REPLACE TYPE NT_TY_BOOKS AS TABLE OF TY_BOOKS;
  2  /
Type created.
SQL> CREATE TABLE STUDENT
  2  ( SID NUMBER(10),
  3  CL_NT_BOOKS NT_TY_BOOKS)
  4  NESTED TABLE CL_NT_BOOKS STORE AS CL_NT_BOOKS_TAB;
Table created.
SQL> INSERT INTO student VALUES (1000, NT_TY_BOOKS(TY_BOOKS('Science')))
  2  /
1 row created.
SQL> INSERT INTO student VALUES (1001, NT_TY_BOOKS(TY_BOOKS('Science'),TY_BOOKS('Maths')))
  2  /
1 row created.
SQL>
SQL> SELECT S.SID,B.VC_BOOK_NAME FROM STUDENT S, TABLE(CL_NT_BOOKS) B
  2  WHERE B.VC_BOOK_NAME='Science'
  3  /
       SID VC_BOOK_NAME
      1000 Science
      1001 Science
SQL> What I suggest is most likely to have happened is that you have added a space or some other non-printing cahracter into the book name when you inserted row 1001. If this is not the case then you'll have to do it again in SQL*Plus, cut teh output and paste it here, so we can see what's going on.
Cheers, APC