select a.slip_no, a.slip_dt,a.cust_cd, b.cust_nm, a.dept_cd, d.dept_nm, a.emp_cd, e.kor_nm emp_nm, a.wh_cd, f.wh_nm, 
					a.loc_cd, g.loc_nm, a.vat_gbn, a.tax_gbn, a.item_cd, c.item_nm, a.in_qty order_qty, (a.in_qty - sum(nvl(h.in_qty,0))) in_qty,  
					a.order_price, a.order_amt, a.order_vat, a.order_tot, a.item_remark
			from buy_tempins a
				LEFT JOIN MST_CUST b on a.comp_seq = b.comp_seq and a.cust_seq = b.cust_seq
				LEFT JOIN MST_ITEM c on a.comp_seq = c.comp_seq and a.item_seq = c.item_seq
				LEFT JOIN MST_DEPT d on a.comp_seq = d.comp_seq and a.dept_seq = d.dept_seq
				LEFT JOIN MST_EMP e on a.comp_seq = e.comp_seq and a.emp_cd = e.mem_id
				LEFT JOIN MST_WAREhouse f on a.comp_seq = f.comp_seq and a.wh_seq = f.wh_seq
				left join mst_warehouseloc g on a.comp_Seq =g.comp_seq and a.wh_seq = g.wh_seq and a.loc_seq = g.loc_seq
				left join buy_ins h on a.comp_seq = h.comp_seq and a.slip_no = h.ref_no and a.btmp_seq = h.ref_seq
		WHERE 1=1
		And a.comp_cd = pCOMP_CD
		 And a.slip_dt between pFROM_DT and pTO_DT
		And NVL(a.complete_gbn, 'N') = 'N'
		group by a.slip_no, a.slip_dt,a.cust_cd, b.cust_nm, a.dept_cd, d.dept_nm, a.emp_cd, e.kor_nm , a.wh_cd, f.wh_nm, 
					a.loc_cd, g.loc_nm, a.vat_gbn, a.tax_gbn, a.item_cd, c.item_nm, a.in_qty ,  
					a.order_price, a.order_amt, a.order_vat, a.order_tot, a.item_remark
		
    Order by a.slip_no, a.btmp_seq;

프로시저를 사용하는데요...

그냥 select 하면 데이터가 나오는데 이상하게 프로시저를 사용하면 Group by 표현식이 아니라고 합니다..

이유가 뭘까요...??