Help needed in building a query

Question

Hello,
I am using Oracle DB 11g.
I want to write a query which gives the next and previous rows for a table, depending upon another column A.
That A column value is from 1 to 10.
If i select column value as 3 then i should get data for column value 2 and 4.
And also if i select 10 i should get data for column value 9 and 1.
How to write this query?
Thanks
Edited by: user13305573 on Dec 9, 2010 4:00 AM

Answer 1

Code with some sample data and output
SQL>VARIABLE your_input NUMBER
SQL>exec :your_input := 5
PL/SQL procedure successfully completed.
SQL>
SQL>WITH t
  2  AS
  3  (  SELECT 1 a, 'A1' name FROM DUAL UNION ALL
  4     SELECT 2 a, 'A2' name FROM DUAL UNION ALL
  5     SELECT 3 a, 'A3' name FROM DUAL UNION ALL
  6     SELECT 4 a, 'A4' name FROM DUAL UNION ALL  
  7     SELECT 5 a, 'A5' name FROM DUAL UNION ALL
  8     SELECT 6 a, 'A6' name FROM DUAL UNION ALL  
  9     SELECT 7 a, 'A7' name FROM DUAL UNION ALL
10     SELECT 8 a, 'A8' name FROM DUAL UNION ALL
11     SELECT 9 a, 'A9' name FROM DUAL UNION ALL
12     SELECT 10 a, 'A10' name FROM DUAL
13  )  
14  SELECT *
15    FROM t
16   WHERE a = :your_input - 1
17      OR a = ( SELECT CASE WHEN :your_input  = MAX(a)
18                           THEN  MAX(a) - :your_input + 1
19                           ELSE  :your_input + 1
20                       END
21                 FROM t
22                    );
         A NAM
         4 A4
         6 A6
SQL>
SQL>
SQL>exec :your_input := 10
PL/SQL procedure successfully completed.
SQL>
SQL>WITH t
  2  AS
  3  (  SELECT 1 a, 'A1' name FROM DUAL UNION ALL
  4     SELECT 2 a, 'A2' name FROM DUAL UNION ALL
  5     SELECT 3 a, 'A3' name FROM DUAL UNION ALL
  6     SELECT 4 a, 'A4' name FROM DUAL UNION ALL  
  7     SELECT 5 a, 'A5' name FROM DUAL UNION ALL
  8     SELECT 6 a, 'A6' name FROM DUAL UNION ALL  
  9     SELECT 7 a, 'A7' name FROM DUAL UNION ALL
10     SELECT 8 a, 'A8' name FROM DUAL UNION ALL
11     SELECT 9 a, 'A9' name FROM DUAL UNION ALL
12     SELECT 10 a, 'A10' name FROM DUAL
13  )  
14  SELECT *
15    FROM t
16   WHERE a = :your_input - 1
17      OR a = ( SELECT CASE WHEN :your_input  = MAX(a)
18                           THEN  MAX(a) - :your_input + 1
19                           ELSE  :your_input + 1
20                       END
21                 FROM t
22                    );
         A NAM
         1 A1
         9 A9Regards
Arun