Question

Somebody mailed me a list with codes, and I need to check whether each code does exist in an oracle 10 database table.

list looks something like:

code1, code2, code3

Of course for every item in the list i can do

select id from my_table where code = 'code1'.

But this would be time consuming, and not a very elegant. I would like to report back a list like:

code1        present
code2        X
code3        X
code4        present

I’m vaguely aware of oracle’s With statement, but I’m not sure how to use it with a list of values instead of a subquery.

Answer 1

The inverse can be achieved like this (see all codes from the database, and check whether they are in the list provided by your colleague):

select code, case when code in ('code1', 'code2', 'code3') 
                  then 'present' 
                  else 'X' end
from my_table;

If that won’t work for you, you can try this:

-- you need a special type for your request. Adapt dimensions if necessary
create type codes as varray(100) of varchar(100);

select c.column_value, case when exists (
  select 1 
  from my_table m 
  where m.code = c.column_value
) then 'present' else 'X' end
from table(codes('code1', 'code2', 'code3')) c;

-- drop that type again
drop type codes;