ORA-02291: integrity constraint (IGLOO.MS_TRANS_FK21185950593156) violated - parent key not found

COM_CD                                                    CONSTANT
    Value is '01'
DEALER_CD                            NEXT     *   ,  O(") CHARACTER            
    SQL string for column : "LPAD(RECNUM, 10, '0')"
LOC_CD                                                    CONSTANT
    Value is '01'

Record 1: Rejected - Error on table DEALER_INFO, column DEALER_CD.
ORA-00984: column not allowed here

load data
infile 'M:\dbf_only\ms_dtl.TXT'
into table ms_trans
replace
fields terminated by ","
optionally enclosed by '"'
trailing nullcols
(
com_Cd CONSTANT "01",
trans_Date      date 'yyyymmdd',
descript,
amount,
trans_cd char(10) "LPAD(ROWNUM, 10, '0')",
dk_no
)

	SELECT COUNT(*) INTO M_dealer_CD FROM dealer_INFO where com_Cd=:global.com_Cd ;
			IF M_dealer_CD = 0 THEN
			M_dealer_CD:=1;
			M_dealer_CD:=LPAD(M_dealer_CD,10,'0');
 		ELSE
			SELECT MAX(dealer_CD)+1 iNTO M_dealer_CD FROM dealer_INFO where com_Cd=:global.com_Cd ;
			M_dealer_CD:=LPAD(M_dealer_CD,10,'0');		
		END IF;

column_name [POSITION({start | *[+offset]}[{: | -}end])]
[datatype] [PIECED]
[NULLIF condition [AND condition...]]
[DEFAULTIF condition [AND condition...]]
["sql_expression"]

CREATE OR REPLACE  FUNCTION "IGLOO"."MAX_DEALER"  (p_com_CD 
    varchar2) RETURN varchar2 IS
m_dealer_CD varchar2(10);
BEGIN
SELECT COUNT(*) INTO M_dealer_CD FROM dealer_INFO where com_Cd=p_com_Cd;
	IF M_dealer_CD = 0 THEN
		M_dealer_CD:=1;
		M_dealer_CD:=LPAD(M_dealer_CD,10,'0');
    return (m_dealer_cd);
	ELSE
		SELECT MAX(dealer_CD)+1 iNTO M_dealer_CD FROM dealer_INFO where com_Cd=p_com_Cd;
		M_dealer_CD:=LPAD(M_dealer_CD,10,'0');		
    return (m_dealer_cd);
	END IF;
	

Record 2: Rejected - Error on table DEALER_INFO, column DEALER_CD.
ORA-04091: table IGLOO.DEALER_INFO is mutating, trigger/function may not see it
ORA-06512: at "IGLOO.MAX_DEALER", line 4