A query with row and colum numbers?

Question

Hello,
i have my java code divided into if conditions and in each if clause i need to select a certain field from a table. Is it somehow possible to select a table field which for example is in the third row and fifth column? So basically, how to select a certain matrix element?
Thank you:)
Edited by: user10956166 on Apr 5, 2009 6:09 AM

Answer 1

Hi,
Assuming you have a table called Distance:
Connected to Oracle Database 10g Express Edition Release 10.2.0.1.0
Connected as hr
SQL> DESCRIBE DISTANCE;
Name    Type         Nullable Default Comments
LINN    VARCHAR2(30) Y                        
TALLINN NUMBER       Y                        
TARTU   NUMBER       Y                        
P2RNU   NUMBER       Y                        
SQL> select * from distance;
LINN                              TALLINN      TARTU      P2RNU
TALLINN                                 0        186        128
TARTU                                 186          0        174
P2RNU                                 128        174          0
SQL>
SQL> SET SERVEROUTPUT ON
SQL> DECLARE
  2     v_sql         VARCHAR2(4000);
  3     v_column_name VARCHAR2(30):= 'TARTU';
  4     v_to          VARCHAR2(30):= 'P2RNU';
  5     v_distance    NUMBER;
  6  BEGIN
  7     v_sql := 'SELECT ' || v_column_name || ' FROM DISTANCE d WHERE d.LINN = ''' || v_to || '''';
  8     EXECUTE IMMEDIATE v_sql
  9        INTO v_distance;
10 
11     dbms_output.put_line(v_distance);
12 
13  EXCEPTION
14     WHEN OTHERS THEN
15        dbms_output.put_line(SQLERRM);
16  END;
17  /
174
PL/SQL procedure successfully completed
SQL> Regards,