Ordering a non-database block....

Question

Hi ,
Is it possible to order and how a non-database block according to user's willing...????
Thanks , a lot
Simon

Answer 1

That will work in sql*plus but to use it in a program you'll need to parameterise the Order By clause. That's why I wrote mine the way I did. It will work in sql*plus if you enter 'A' and 'B' (including the quotes) and it will work in a program if you replace the placeholders with variables.
SQL> WITH data AS(
  2    SELECT 1 a, 9 b FROM dual UNION ALL
  3    SELECT 1 a, 1 b FROM dual UNION ALL
  4    SELECT 1 a, 8 b FROM dual UNION ALL
  5    SELECT 1 a, 2 b FROM dual UNION ALL
  6    SELECT 1 a, 7 b FROM dual UNION ALL
  7    SELECT 2 a, 8 b FROM dual UNION ALL
  8    SELECT 3 a, 7 b FROM dual UNION ALL
  9    SELECT 4 a, 6 b FROM dual UNION ALL
10    SELECT 5 a, 5 b FROM dual UNION ALL
11    SELECT 6 a, 4 b FROM dual UNION ALL
12    SELECT 7 a, 3 b FROM dual UNION ALL
13    SELECT 8 a, 2 b FROM dual UNION ALL
14    SELECT 9 a, 1 b FROM dual
15  )
16  SELECT a, b FROM data
17  ORDER BY
18    Decode(&ordr1,'A',a,'B',b),
19    Decode(&ordr2,'A',a,'B',b)
20  ;
Enter value for ordr1: 'A'
old  18:   Decode(&ordr1,'A',a,'B',b),
new  18:   Decode('A','A',a,'B',b),
Enter value for ordr2: 'B'
old  19:   Decode(&ordr2,'A',a,'B',b)
new  19:   Decode('B','A',a,'B',b)
         A          B
         1          1
         1          2
         1          7
         1          8
         1          9
         2          8
         3          7
         4          6
         5          5
         6          4
         7          3
         8          2
         9          1
13 rows selected.
SQL> /
Enter value for ordr1: 'B'
old  18:   Decode(&ordr1,'A',a,'B',b),
new  18:   Decode('B','A',a,'B',b),
Enter value for ordr2: 'A'
old  19:   Decode(&ordr2,'A',a,'B',b)
new  19:   Decode('A','A',a,'B',b)
         A          B
         1          1
         9          1
         1          2
         8          2
         7          3
         6          4
         5          5
         4          6
         1          7
         3          7
         1          8
         2          8
         1          9
13 rows selected.
SQL> var ordr1 varchar2(1);
SQL> var ordr2 varchar2(1);
SQL> exec :ordr1 := 'A';
PL/SQL procedure successfully completed.
SQL> exec :ordr2 := 'B';
PL/SQL procedure successfully completed.
SQL> WITH data AS(
  2    SELECT 1 a, 9 b FROM dual UNION ALL
  3    SELECT 1 a, 1 b FROM dual UNION ALL
  4    SELECT 1 a, 8 b FROM dual UNION ALL
  5    SELECT 1 a, 2 b FROM dual UNION ALL
  6    SELECT 1 a, 7 b FROM dual UNION ALL
  7    SELECT 2 a, 8 b FROM dual UNION ALL
  8    SELECT 3 a, 7 b FROM dual UNION ALL
  9    SELECT 4 a, 6 b FROM dual UNION ALL
10    SELECT 5 a, 5 b FROM dual UNION ALL
11    SELECT 6 a, 4 b FROM dual UNION ALL
12    SELECT 7 a, 3 b FROM dual UNION ALL
13    SELECT 8 a, 2 b FROM dual UNION ALL
14    SELECT 9 a, 1 b FROM dual
15  )
16  SELECT a, b FROM data
17  ORDER BY
18    Decode(:ordr1,'A',a,'B',b),
19    Decode(:ordr2,'A',a,'B',b)
20  ;
         A          B
         1          1
         1          2
         1          7
         1          8
         1          9
         2          8
         3          7
         4          6
         5          5
         6          4
         7          3
         8          2
         9          1
13 rows selected.
SQL> exec :ordr1 := 'B';
PL/SQL procedure successfully completed.
SQL> exec :ordr2 := 'A';
PL/SQL procedure successfully completed.
SQL> /
         A          B
         1          1
         9          1
         1          2
         8          2
         7          3
         6          4
         5          5
         4          6
         1          7
         3          7
         1          8
         2          8
         1          9
13 rows selected.
SQL>