Problem while modifying number datatype.

Question

Hi All,
I have modified a column, which is of number datatype.
Initially it was number(8,2), now I have changed this to Number(10,2).
But, due to some change in requirement, I have to revese the changes. Now, I am trying to make it Number(8,2), but it is giving me the following error.
Error report:
SQL Error: ORA-01440: column to be modified must be empty to decrease precision or scale
01440. 00000 - "column to be modified must be empty to decrease precision or scale"
Is there a way to make it?
Please suggest..
I am using Oracle Database 11g Enterprise Edition Release 11.1.0.7.0 - 64bit Production.
Thnx in advance..
Bits..

Answer 1

You'd have to jump through some hoops to decrease the allowable number of digits in a column. You'd either have to re-create the table, i.e.
-- Save off the data in FOO
ALTER TABLE foo
  RENAME TO foo_bkup;
CREATE TABLE foo (
  -- New column definitions
INSERT /*+ APPEND */ INTO foo( list_of_columns )
  SELECT list_of_columns
    FROM foo_bkupOr you could create a new column, copy the data, and rename the old column
ALTER TABLE foo
   ADD( temp_col_name number(8,2) );
UPDATE foo
   SET temp_col_name = old_col_name;
ALTER TABLE foo
  DROP COLUMN old_col_name;
ALTER TABLE foo
  RENAME COLUMN temp_col_name TO old_col_name;Justin