Finding the numbers which are not consecutive in an order....

Question

Hi,
The solution i found was using the minus set operation:
SQL> create table test as
  2    mplestselect 1 a from dual
  3  union all
  4  select 3 a from dual;
Table created
SQL>
SQL> select level
  2      from dual
  3      connect by level<=10
  4    minus
  5   select a from test
  6  /
     LEVEL
         2
         4
         5
         6
         7
         8
         9
        10
8 rows selectedQuestions:
1) Is there any other solution...(i'm convinced there is even simpler....)
2) Trying in the above sql stmt not to create the table test... i tried the following :
but the error appearerd...
with sample as
  (select level
    from dual
    connect by level<=10),
            x as
            (select 1 a from dual
             union all
          select 2 a from dual
             union all
             select 7 a from dual)
select level from sample
  minus
select a from x
ORA-01788:required connect by expression in this query blockHow could i edit the query without creating the "test" table...????
Thank you,
Sim

Answer 1

Hi, Sim,
sgalaxy wrote:
Questions:
1) Is there any other solution...(i'm convinced there is even simpler....)Not that I know of (assuming I understand the problem).
2) Trying in the above sql stmt not to create the table test... i tried the following :
but the error appearerd...
with sample as
(select level
from dual
connect by level<=10),
x as
(select 1 a from dual
union all
          select 2 a from dual
union all
select 7 a from dual)
select level from sample
minus
select a from x
ORA-01788:required connect by expression in this query blockHow could i edit the query without creating the "test" table...????Don't name your columns the same as pseudo-columns (like LEVEL), built-in functions, reserved words, etc.
Use a column alias, like this:
with sample as
  (select level  AS level_num        -- Alias defined
    from dual
    connect by level<=10),
            x as
            (select 1 a from dual
             union all
          select 2 a from dual
             union all
             select 7 a from dual)
select level_num from sample        -- Alias referenced
  minus
select a from x