Помогите составить запрос на выборку

CREATE TABLE Customer
(
    CustNo      INTEGER,
    FirstName   VARCHAR2(20),
    LastName    VARCHAR2(20),
    Address     VARCHAR2(50),
    City        VARCHAR2(20),
    State       CHAR(2),
    PostalCode  CHAR(6),
    PhoneNumber CHAR(12),
CONSTRAINT PKCustNo PRIMARY KEY (CustNo)
);
 
CREATE TABLE Part
(
    PartNo      INTEGER,
    PartDesc    VARCHAR2(40),
    UnitInStock INTEGER,
    UnitPrice   DECIMAL(5,2),
    UnitSize    VARCHAR2(15),
CONSTRAINT PKPartNo PRIMARY KEY(PartNo)
);
 
CREATE TABLE PartsUsed
(
    OrdNo       INTEGER,
    PartNo      INTEGER,
    QtyUsed     INTEGER,
CONSTRAINT PKPartsUsed PRIMARY KEY(OrdNo, PartNo),
CONSTRAINT FKOrdNo FOREIGN KEY (OrdNo) REFERENCES RepairOrder,
CONSTRAINT FKPartNo FOREIGN KEY (PartNo) REFERENCES Part
);
 
CREATE TABLE RepairOrder
(
    OrdNo       INTEGER,
    Odometer    INTEGER,
    TimeRecvd   DATE,
    TimeFinish  DATE,
    PhoneWnRdy  CHAR(1) DEFAULT 'Y',
    SerialNo    VARCHAR2(10),
CONSTRAINT check_phone CHECK (PhoneWnRdy IN ('Y', 'N')),
CONSTRAINT PKOrdNo PRIMARY KEY(OrdNo),
CONSTRAINT FKSerialNo FOREIGN KEY (SerialNo) REFERENCES Vehicle
);
 
CREATE TABLE Vehicle
(
    SerialNo    VARCHAR2(10),
    YEAR        INTEGER,
    Make        VARCHAR2(12),
    Model       VARCHAR2(15),
    LicenseNo   VARCHAR2(6),
    State       CHAR(2),
    Cylinders   INTEGER,
    CustNo      INTEGER,
CONSTRAINT PKSerialNo PRIMARY KEY(SerialNo),
CONSTRAINT FKCustNo FOREIGN KEY (CustNo) REFERENCES Customer
);

SELECT c.FirstName
  , c.LastName
FROM Customer c
  , Vehicle v
WHERE c.CustNo = v.CustNo
  AND v.SerialNo NOT IN (SELECT SerialNo FROM RepairOrder)