SQL & PL/SQL

Oracle DB 12.1.0.2
EBS 12.1
AIX 6
Hello Team,

could you please advise how to rewrite the following functions?

select  distinct inventory_item_id, segment1 Item_code, apps.xx_mtg_get_last_poprice(inventory_item_id) Last_PO_Price, 
apps.xxmtg_get_max_issuedate(inventory_item_id) Last_Issue_Date 
from inv.mtl_system_items_b;

apps.xx_mtg_get_last_poprice(inventory_item_id)

create or replace FUNCTION   xx_mtg_get_last_poprice (p_itemid IN NUMBER)
  RETURN varchar2
IS
  last_po_price  varchar2(100);
BEGIN
  SELECT max(pha.CURRENCY_CODE)||' ' ||round(max(pla.UNIT_PRICE),2)
   INTO last_po_price
   FROM po_lines_all pla, po_headers_all pha
  WHERE NVL (pla.cancel_flag, 'N') = 'N'
   AND pla.po_header_id = pha.po_header_id
   AND pha.approved_flag = 'Y'
   AND pla.item_id = p_itemid
   AND pha.po_header_id =
       (SELECT MAX (pla.po_header_id)
        FROM po_lines_all pla, po_headers_all pha
        WHERE NVL (pla.cancel_flag, 'N') = 'N'
         AND pla.po_header_id = pha.po_header_id
         AND pha.approved_flag = 'Y'
         AND pla.item_id = p_itemid);
  RETURN last_po_price;
END;

apps.xxmtg_get_max_issuedate(inventory_item_id)

create or replace FUNCTION   xxmtg_get_max_issuedate(p_item_id IN NUMBER)
  RETURN DATE
AS
--M. Claire Lock Son
--Function to get the last issue date for a stock item with onhand qty > 0
  last_date_issued  DATE;
BEGIN
  select max(transaction_date) 
  INTO last_date_issued
  from mtl_material_transactions 
  where inventory_item_id = p_item_id 
  and transaction_action_id=1;

  RETURN last_date_issued;
EXCEPTION
  --When no_data_found then
  --     Return 'Null';
  WHEN OTHERS
  THEN
   RETURN NULL;
END; 

I tried to create 1 view for each function
for price

select b.inventory_item_id inventory_item_id, concat_ws(' ',max(pha.CURRENCY_CODE),cast(max(cast(pla.UNIT_PRICE as decimal(10,2))) as string)) codeprice
   FROM oracle_financial.po_lines_all pla, oracle_financial.po_headers_all pha,oracle_financial.mtl_system_items_b b,of_cubes.xx_mtg_get_last_poprice1 xx
  WHERE NVL (pla.cancel_flag, 'N') = 'N'
   AND pla.po_header_id = pha.po_header_id
   AND pha.approved_flag = 'Y'
   AND pla.item_id = b.inventory_item_id
   AND pha.po_header_id =xx.phi
   group by b.inventory_item_id;

and 1 for date

select a.inventory_item_id,max(a.transaction_date) Last_Issue_Date,b.segment1
  from oracle_financial.mtl_material_transactions a,oracle_financial.mtl_system_items_b b
  where a.inventory_item_id = b.inventory_item_id
  and transaction_action_id=1
group by a.inventory_item_id,b.segment1;

Kindly advise how can I combine these?

Thanks,

Roshan