Question

I am using Oracle and have a table containing a long datatype. I have since discovered that this is legacy and I should have used a LOB. I also now think I could probably just use NUMBER(10,0).

I want to convert the column from a long datatype to a NUMBER datatype.

Here is my SQL so far.

ALTER TABLE BUDGET ADD AMT2 NUMBER(10,0);
UPDATE BUDGET SET AMT2 = AMT;
ALTER TABLE BUDGET DROP COLUMN AMT;
ALTER TABLE BUDGET RENAME COLUMN AMT2 TO AMT;

The AMT columns is LONG
The new AMT2 column is my new column of NUMBER(10, 0)

The problem is that when assigning the long to a number I get an error. This is on the update line (line2) This I presume is because of data truncation.

The error is

SQL Error: ORA-00932: inconsistent datatypes: expected NUMBER got LONG

All the data in the column is less than 10000 so I want to force oracle to ignore any data truncation (because I dont believe there should be any). How can I assign the long data to a number data column?

Thanks

Answer 1

Create a PL/SQL Function to get the Long as the data-type you need.

Example:

create or replace 
function longtonumber( p_rowid in rowid)
return number
 as
      l_data long;
 begin
     select remarks into l_data from cr_claimheader where rowid = p_rowid;
      return to_number(substr( l_data, 1, 4000 ));
end;

Then all you need to do is update using this function in your update statement:
update am1=longtonumber(amt2)…etc.

I got this from askTom: http://asktom.oracle.com/pls/asktom/f?p=100:11:0::::P11_QUESTION_ID:839298816582