$1\mathrm{.}2$ Write a relational algebra from this question using bag semantic.

$--$Question $1\mathrm{.}1$

SELECT users.usercode AS UserCode,

AVG$($hotels$.$pricepernight $*$ hotels.days$)$ AS AvgHotelPrice

FROM users

JOIN hotels ON users.usercode $=$ hotels.usercode

GROUP BY UserCode;

$1\mathrm{.}4$ Write a relational algebra $--$ Question $1\mathrm{.}3$

SELECT H$1.$travelcode AS TravelCode,

H$1.$usercode AS UserCode

FROM hotels H$1$

JOIN hotels H$2$ ON H$1.$hotelname $=$ H$2.$hotelname

AND H$1.$checkindate $<$ H$2.$checkoutdate

AND H$2.$checkindate $<$ H$1.$checkoutdate

WHERE H$1.$travelcode $<>$ H$2.$travelcode

AND H$1.$usercode $=$ H$2.$usercode;

$--$Question $1\mathrm{.}4$: Write a relational bag semnatic algebra for this question:

SELECT travelcode,

flightprice $+($pricepernight $*$ days$)$ AS TotalCost,

CASE

WHEN flightprice $+($pricepernight $*$ days$)>3000$ THEN 'Luxury'

WHEN flightprice $+($pricepernight $*$ days$)<1000$ THEN 'Cheap'

ELSE 'Regular'

END AS TripClass

FROM hotels

JOIN flights ON hotels.travelcode $=$ flights.travelcode;