Функция подсчета из разных полей APEX

CREATE TABLE  "BLUDES" 
   (    "ID" VARCHAR2(10) NOT NULL ENABLE, 
    "B_NAME" VARCHAR2(64) NOT NULL ENABLE, 
    "B_INGRES" NUMBER, 
    "PRICE" NUMBER, 
    "IMAGE" BFILE, 
    "B_TYPE" NUMBER, 
     CONSTRAINT "BLUDES_PK" PRIMARY KEY ("ID") ENABLE
   )
/
 
CREATE OR REPLACE TRIGGER  "BI_BLUDES" 
  before INSERT ON "BLUDES"               
  FOR each ROW  
BEGIN   
  IF :NEW."ID" IS NULL THEN 
    SELECT "BLUDES_SEQ".NEXTVAL INTO :NEW."ID" FROM sys.dual; 
  END IF; 
END; 
 
/
ALTER TRIGGER  "BI_BLUDES" ENABLE
/

CREATE TABLE  "INGTES" 
   (    "ID" NUMBER, 
    "I_NAME" VARCHAR2(64) NOT NULL ENABLE, 
    "I_DATE" DATE NOT NULL ENABLE, 
    "I_PRICE" NUMBER(6,2) NOT NULL ENABLE, 
    "I_COUNT" NUMBER(7,3) NOT NULL ENABLE, 
    "I_TYPE" NUMBER, 
     CONSTRAINT "INGTES_PK" PRIMARY KEY ("ID") ENABLE
   )
/
 
CREATE OR REPLACE TRIGGER  "BI_INGTES" 
  before INSERT ON "INGTES"               
  FOR each ROW  
BEGIN   
  IF :NEW."ID" IS NULL THEN 
    SELECT "INGTES_SEQ".NEXTVAL INTO :NEW."ID" FROM sys.dual; 
  END IF; 
END; 
 
/
ALTER TRIGGER  "BI_INGTES" ENABLE
/

CREATE TABLE  "INGRES_FOR_BLUD" 
   (    "ID" NUMBER NOT NULL ENABLE, 
    "B_ID" NUMBER, 
    "I_ID" NUMBER, 
    "COUNT" NUMBER, 
     CONSTRAINT "INGRES_FOR_BLUD_PK" PRIMARY KEY ("ID") ENABLE
   )
/
 
CREATE OR REPLACE TRIGGER  "BI_INGRES_FOR_BLUD" 
  before INSERT ON "INGRES_FOR_BLUD"               
  FOR each ROW  
BEGIN   
  IF :NEW."ID" IS NULL THEN 
    SELECT "INGRES_FOR_BLUD_SEQ".NEXTVAL INTO :NEW."ID" FROM sys.dual; 
  END IF; 
END; 
 
/
ALTER TRIGGER  "BI_INGRES_FOR_BLUD" ENABLE
/