PlSQL trigger error ORA-0000 ORA-06512:

create or replace 
TRIGGER "SUP" AFTER INSERT ON "EMP_REPORT" REFERENCING OLD AS "OLD" NEW AS "NEW" FOR EACH ROW
DECLARE

  miclaim_supervisor_count number;
  employee_company_code VARCHAR2(10);
  employee_businessunit number;
  projMgrs NUMBER;
  supId NUMBER;

  cursor  projMgrsCursor is select b.BU_MEMBER_ID
  from BU_MEMBER b, EMP_SUB_DIV s
  where s.EMP_NO = :NEW.EMP_NO
  and s.SUB_DIVISION_CODE = '01' and s.DIV_CODE = '2'
  and b.BU_ID IN (select BU_ID from BU_MEMBER where BU_MEMBER_ID = :NEW.EMP_NO);


BEGIN
        delete from MICL_SUPERVISORS where EMP_NO = :NEW.EMP_NO and IS_OVVERRIDDEN = 0;
        select count(*) into miclaim_supervisor_count from MICL_SUPERVISORS where EMP_NO = :NEW.EMP_NO and IS_OVVERRIDDEN = 1;
        select COMPANY_CODE into employee_company_code from  EMPLOYEE_MASTER where EMP_NO = :NEW.EMP_NO;


    projMgrs := 0;

if (employee_company_code ='F')then 

  OPEN  projMgrsCursor;
    LOOP

     select micl_sup_id_seq.nextval into  supId from dual;
    FETCH projMgrsCursor INTO projMgrs;
    EXIT WHEN projMgrsCursor%NOTFOUND;

    insert into SUP VALUES ((supId), (SELECT SYSDATE FROM DUAL), :NEW.ENTRYADDEDBY_EMP_NO, 3000, 0,projMgrs, NULL,:NEW.EMP_NO);
    END LOOP;   

  CLOSE projMgrsCursor;
else
    if(miclaim_supervisor_count IS NULL or miclaim_supervisor_count<1) then
    insert into SUP VALUES ((:NEW.ID), (SELECT SYSDATE FROM DUAL), :NEW.ENTRYADDEDBY_EMP_NO, 3000, 0, :NEW.SUP_EMP_NO, NULL,:NEW.EMP_NO);
    end if;
end if;

END;

I created this trigger a week go but no compilation errors But when I enter a record to EMP_REPORT it pop up an error msg saying

 *INSERT INTO"EMP_REPORT" (ID, ADDEDDATE, ENTRYADDEDBY_EMP_NO, SUP_EMP_NO, EMP_NO) VALUES ('71', TO_TIMESTAMP('19-MAR-13 09.55.57.983000000 AM', 'DD-MON-RR HH.MI.SS.FF AM'), '81', '841', '5295')
ORA-00001: unique constraint (SYS_C0023329) violated
ORA-06512: at line 1

One error saving changes to table  "EMP_REPORT":
Row 51: ORA-00001: unique constraint (SYS_C0023329) violated
ORA-06512: at line 1* 

I cant figure out where I went wrong. pls help me :(

pls note that I cant remove constraint and its a primary key

Are you sure that the error occurs in the trigger? It looks to me like the INSERT which might be failing is the one into EMP_REPORT - possibly because there's already a row in EMP_REPORT with ID = '71'. It would be helpful if you could confirm what table SYS_C0023329 is on.

However, assuming that the message is being generated by the trigger - I only see two INSERTs in your trigger, both inserting into the SUP table, so the problem must be coming from one of these INSERTs. Either

1. There's already a row in SUP which has a key value (you don't show the names of the columns in your INSERT statements against SUP so I don't know what the field's name might be) greater than the current value of MICL_SUP_ID_SEQ.NEXTVAL, or

2. There's a row in SUP with a key value equal to the new EMP_REPORT.ID field you've supplied in the second INSERT.

This second issue, supplying a key value from one table (EMP_REPORT) as the key value for a second table (SUP) seems a bit suspicious to me, and I'd suggest looking there first. I'd think you'd want to get a value from MICL_SUP_ID_SEQ to use in the SUP table.

To verify that the issue is caused by an insert into SUP, you might try executing the following:

SELECT *
  FROM ALL_CONSTRAINTS c
  WHERE c.CONSTRAINT_NAME = 'SYS_C0023329';

This will tell you what table the constraint is on.

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