CREATE OR REPLACE TRIGGER logbstp2
AFTER insert ON bs_table for each row
declare
PRAGMA autonomous_transaction; 
i_spid 	sales_pnt.pk_sales_pnt_id%type;
spid number;
v_count number;
i_tran_date		date;
v_inputted_date    date;
cursor c1 is select pk_sales_pnt_id  from sales_pnt;
BEGIN
open c1;
fetch c1 into spid ;
v_inputted_date := i_tran_date;
select count(1) into v_count from bs_table where inputted_date = v_inputted_date;
   IF v_count = 0  THEN
    update 	bs_table
	set 	volt_tp_id = 2,
			inputted_date = v_inputted_date,
			sales_pnt_id = spid
	where 	inputted_date IS NULL;
	commit;
	end if;
END;
/

ERROR at line 1:
ORA-04091: table bs_table is mutating, trigger/function
may not see it
ORA-06512: at "LOGBSTP2", line 12
ORA-04088: error during execution of trigger 'LOGBSTP2'
ORA-06512: at "BS_PKG", line 249
ORA-06512: at line 1

MERGE INTO  bILL BS
   USING (select s.pk_sales_pnt_id FROM sales_pnt s, bill b
           where b.sales_pnt_id = pk_sales_pnt_id
		   and b.volt_tp_id is null
		     )sp
      ON (bs.sales_pnt_id <> Sp.pk_sales_pnt_id)
   WHEN MATCHED THEN update 	set 
	 	bs.volt_tp_id = 2,
			bs.inputted_date=v_inputted_date,
			bs.sales_pnt_id = pk_sales_pnt_id
	where 	bs.volt_tp_id is null;

ERROR at line 1:
ORA-38104: Columns referenced in the ON Clause cannot be updated:
"BS"."SALES_PNT_ID"
ORA-06512: at "sTest.MBS_PKG", line 884
ORA-06512: at line 1