unique constraint error

I have a table A :

CREATE TABLE A (
column1 VARCHAR2 (2) NOT NULL, column2 VARCHAR2 (4) NOT NULL, column3 VARCHAR2 (2) NOT NULL, column4 VARCHAR2 (6) NOT NULL, column5 CHAR (8) NOT NULL, column6 CHAR (8),

column7 CHAR (1), column8 CHAR (1))

There are 5 index on the first 5 columns: CREATE UNIQUE A_IU ON "SCHEMA".A(column1 , column2 , column3 , column4 , column5 )

TABLESPACE IDX_APP_A PCTFREE 5 STORAGE(INITIAL 16384 NEXT 8192 PCTINCREASE 0 ) ;

I have a stored procedure which does either an INSERT :

INSERT INTO A ( column1 , column2 , column3 , column4 , column5 , column6 , column7 , column8 )

   VALUES ( val1, val2, val3, val4, val5, val6, NULL, NULL , NULL);

or an UPDATE :
UPDATE A SET column6 = val11 AND column3 = val3 AND column4 = val4;

Of course if the record already exists in the table, it raises a unique constraint error.

How do i do to avoid this error ?
thanks for your help Received on Fri Jul 19 2002 - 10:39:12 CDT