Function to get Invoice number,invoice Amount,invoice type lookup code by passing invoice id and org id as parameter

CREATE OR REPLACE FUNCTION getinv (p1 IN NUMBER, p2 NUMBER)
   RETURN VARCHAR
AS
   v_invno   VARCHAR2 (50);
BEGIN
   SELECT invoice_num
     INTO v_invno
     FROM ap_invoices_all a
    WHERE a.invoice_id = p1 AND a.org_id = p2;

   RETURN v_invno;
END;
/

CREATE OR REPLACE FUNCTION getinvamt (p1 IN NUMBER)
   RETURN NUMBER
AS
   v_amt   ap_invoices_all.invoice_

amount%TYPE;
BEGIN
   SELECT invoice_amount
     INTO v_amt
     FROM ap_invoices_all a
    WHERE a.invoice_id = p1;

   RETURN v_amt;
END;
/

CREATE OR REPLACE FUNCTION getinvtype (p1 IN NUMBER)
   RETURN VARCHAR
AS
   v_invno   VARCHAR2 (50);
BEGIN
   SELECT invoice_type_lookup_code
     INTO v_invno
     FROM ap_invoices_all a
    WHERE a.invoice_id = p1;

   RETURN v_invno;
END;
/