sql - Converting Long to Varchar2

Question

I am trying to insert into varchar2 column from a long column. here is the below example, TEXT.TEXT_COL = VARCHAR2(4000) and NOTE.TEXT_NOTE = LONG.

INSERT INTO TEXT(ROW_ID, TEXT_COL)
SELECT 1, TEXT_NOTE FROM NOTE; 

When i run the above sql i get error

SQL Error: ORA-00997: illegal use of LONG datatype

I used TO_LOB() too, but still the same error.

Is there any function which simply coverts long and put it in varchar2. Let me know your thoughts.

Answer 1

Converting from long to varchar2 right away using a single statement is not possible, as long has certain restrictions.

You can either Create a temporary table or use PL/SQL code to solve your problem:

• Temporary Table:

  CREATE TABLE TABLE2 AS SELECT TO_LOB(COLUMN1) COLUMN FROM TABLE1;

• PL/SQL Code:

  DECLARE
    VAR1 LONG;
    VAR2 VARCHAR2(4000);
  BEGIN
    SELECT TEXT INTO VAR1 FROM USER_VIEWS WHERE ROWNUM = 1;  
    VAR2 := SUBSTR(VAR1, 1, 4000);
    DBMS_OUTPUT.PUT_LINE(VAR2);
  END;