我嘗試創(chuàng)建三個表（CUSTOMERS、VEHICLES 和 RENTALS），第三個表（RENTALS）的外鍵引用前兩個表（CUSTOMERS 和 RENTALS）的兩個主鍵。創(chuàng)建第三個表時，我收到錯誤“ 關(guān)系中缺少列”(Rel=CUSTOMERS[[]] -> RENTALS[[]])這是我的代碼     private void createTables() throws SQLException {        Statement statement = conn.createStatement();        statement.executeUpdate("CREATE TABLE CUSTOMERS(custNumber AUTOINCREMENT PRIMARY KEY, " +            "firstName VARCHAR(155) NOT NULL, surname VARCHAR(155) NOT NULL, idNum INTEGER NOT NULL, phoneNum INTEGER NOT NULL, canRent BIT NOT NULL)");        statement.executeUpdate("CREATE TABLE VEHICLES(vehNumber AUTOINCREMENT PRIMARY KEY, make VARCHAR(155) NOT NULL, " +            "category VARCHAR(155) NOT NULL, rentalPrice FLOAT NOT NULL, availableForRent BIT NOT NULL)");        statement.executeUpdate("CREATE TABLE RENTALS(rentalNumber AUTOINCREMENT PRIMARY KEY, dateRental VARCHAR(155) NOT NULL, dateReturned VARCHAR(155) NOT NULL, " +            "pricePerDay FLOAT NOT NULL, totalRental FLOAT NOT NULL, custNumber INTEGER FOREIGN KEY REFERENCES CUSTOMERS(custNumber), " +            "vehNumber INTEGER FOREIGN KEY REFERENCES VEHICLES(vehNumber))");        System.out.println("Database populated");     }這是錯誤