plsql get column names by table value

Question

I have a table T with one row value only, the names are column names and 'not' or 'enrolled' are values

Jack      |    Mary  |   Tom    |  Peter |

enrolled  |   not    |enrolled  | not   |

Is there any way I can return the column names where their values are 'not'

sample result set:

| Mary | Peter |

Answer 1

If there is still time to redesign your table + data, consider changing it to something like this instead:

 name  |  is_enrolled
 ----     -----------
 Jack          1
 Mary          0
  Tom          1
Peter          0

This way, you can use simpler SQL to do what you want:

select name from table_name where is_enrolled = 0

Answer 2

You seem to have a very bad data format. And a SQL query returns a fixed number of columns. So, you cannot do what you want by returning values.

You can, however, create a string with the column names:

select ((case when Jack = 'not' then 'Jack ' else '' end) ||
        (case when Mary = 'not' then 'Mary ' else '' end) ||
        (case when Tom = 'not' then 'Tom ' else '' end) ||
        (case when Peter = 'not' then 'Peter ' else '' end)
       ) TheNots
from t;