Oracle - select a specific column from a ref cursor

You can do this with DBMS_SQL, but it ain't pretty.

Table and sample data (COLUMN1 has the numbers 1 - 10):

create table table1(column1 number, column2 date, column3 varchar2(1000), column4 clob);insert into table1select level, sysdate, level, level from dual connect by level <= 10;commit;

Package with a procedure that opens a ref cursor and selects everything:

create or replace package test_pkg is    type cur_Table1 is ref cursor return table1%rowtype;    procedure sp1(p_cursor in out cur_table1);end;/create or replace package body test_pkg is    procedure sp1(p_cursor in out cur_table1) is    begin        open p_cursor for select column1, column2, column3, column4 from table1;    end;end;/

PL/SQL block that reads COLUMN1 data from the ref cursor:

--Basic steps are: call procedure, convert cursor, describe and find columns,--then fetch rows and retrieve column values.----Each possible data type for COLUMN1 needs to be added here.--Currently only NUMBER is supported.declare    v_cursor sys_refcursor;    v_cursor_number number;    v_columns number;    v_desc_tab dbms_sql.desc_tab;    v_position number;    v_typecode number;    v_number_value number;begin    --Call procedure to open cursor    test_pkg.sp1(v_cursor);    --Convert cursor to DBMS_SQL cursor    v_cursor_number := dbms_sql.to_cursor_number(rc => v_cursor);    --Get information on the columns    dbms_sql.describe_columns(v_cursor_number, v_columns, v_desc_tab);    --Loop through all the columns, find COLUMN1 position and type    for i in 1 .. v_desc_tab.count loop        if v_desc_tab(i).col_name = 'COLUMN1' then            v_position := i;            v_typecode := v_desc_tab(i).col_type;            --Pick COLUMN1 to be selected.            if v_typecode = dbms_types.typecode_number then                dbms_sql.define_column(v_cursor_number, i, v_number_value);            --...repeat for every possible type.            end if;        end if;    end loop;    --Fetch all the rows, then get the relevant column value and print it    while dbms_sql.fetch_rows(v_cursor_number) > 0 loop        if v_typecode = dbms_types.typecode_number then            dbms_sql.column_value(v_cursor_number, v_position, v_number_value);            dbms_output.put_line('Value: '||v_number_value);        --...repeat for every possible type        end if;    end loop;   end;/

Given the original question, jonearles's answer is still correct, so I'll leave it marked as such, but I ended up doing something completely different and much better.

The problem was/is that I have no control over SP1's database, I just have to call it from somewhere else as a 3rd party client. Now I managed to get permission to see not only SP, but also the type of the cursor. I still don't see the table but now there is a much cleaner solution:

In the other database I have been granted access to see this type now:

type cur_Table1 is ref cursor return Table1%rowtype;

So in my database I can do this now:

mycursor OtherDB.cur_Table1;myrecord mycursor%rowtype;...OtherDB.SP1(mycursor);fetch mycursor into myrecord;dbms_output.put_line(myrecord.Column1);

See, I still don't need any access to the table, I see the cursor only. The key is that the magical %rowtype works for cursors as well, not just tables. It doesn't work on a sys_refcursor, but it does on a strongly typed one. Given this code, I don't have to care if anything changes on the other side, I don't have to define all the columns or records at all, I just specify the one column I'm interested in.

I really love this OOP attitude about Oracle.

Don't know if it's an option or not, but wouldn't a better solution be to create a function that returns the specific value you're looking for? That avoids the overhead of sending the extra data. Alternatively, you could define a cursor with a set of known fields in it that both parties know about.