Question

I got a really big problem.
I am writing an App for building a txt-file with some data from the Oracle-DB.

So actually i got a problem with the data_default column (type LONG).

Let’s post some code:

Here’s my Select:

SELECT table_name || '.' || column_name, data_precision, data_type, nullable, data_length, data_default 

Here is my way of reading out the data:

string dataDefault = (dataReader[5].GetType() == typeof(DBNull)) ? "" : Convert.ToString(dataReader.GetString(5))

So maybe it’s not the “pretty” way but i have a big problem with LONG data types here. I can’t get the data from data_default in this way.
I searched on the internet, but i want to solve this problem within C#-Code. If it’s not possible, please don’t overestimate my SQL-knowledge 😉

Have a nice day,
Clemens

Answer 1

I got the answer! After a long time of searching and forging i wanna post the final solution:

create or replace function get_col_default
(
p_owner in all_tab_cols.owner%type,
p_table_name in all_tab_cols.table_name%type,
p_column_name in all_tab_cols.column_name%type
)
return varchar2
as
        l_data_default LONG;
begin
        select data_default into l_data_default
          from all_tab_cols
         where owner = p_owner
           and table_name = p_table_name
           and column_name = p_column_name;

        return substr( l_data_default, 1, 4000 );
end;

And then you can create this query for example:

select a.table_name, a.COLUMN_NAME, get_col_default('exOwner',a.table_name,a.COLUMN_NAME) 
from all_tab_columns a
where  table_name like 'table%'
and owner like 'exOwner'

The good thing about this is, that you can extend that function very easy and won’t be limited to 1 result/execute. (i had this problem in some further ideas)

Have a nice day! 😉