Store Column-Name into variable

Question

Hello from germany
I got stuck with following:
How is it possible to store the name of a column into a variable or is it possible to put an index "on" a column?
The reason for this: I need to fill and check a complete column!
Thanks for Your help!
Best regards
Marlon

Answer 1

Those sure are unrelated questions. Lets say we have a table like this:
SQL> CREATE TABLE t (
  2    a  number,
  3    b  varchar2(8),
  4    c  date );
Table created.You can get a column name like this:
SQL> set serveroutput on
SQL> DECLARE
  2    second_col   VARCHAR2 (30);
  3  BEGIN
  4    SELECT column_name
  5      INTO second_col
  6      FROM user_tab_columns
  7     WHERE table_name = 'T'
  8       AND column_id = 2;
  9    DBMS_OUTPUT.PUT_line(second_col);
10  END;
11  /
B
PL/SQL procedure successfully completed.
SQL> You can put an index on a column like this:
SQL> CREATE INDEX t_n1 ON t(b);
Index created.And you can add data to the table like this:
SQL> insert into t(a, b) values (4, 'asdf');
1 row created.
SQL> select * from t;
         A B        C
         4 asdf
SQL>