The following tables form part of a database held in a relational DBMS (Primary Key,
Foreign Key):
CLIENT (ClientID, ClientName, AnnualRevenue)
VESSEL (VesselNumber, VesselName, MaxWeight)
Driver (DriverID, DriverName)
COUNTRY (CountryName, Population)
TRANSACTION(TransNumber,
ClientID,
DriverID,
VesselNumber,
Departure
CountryName,
Destination
CountryName,
Year, TransactionWeight)
Formulate
relational algebra
(NOT SQL) expressions
for each of the following:
- Names of Drivers who delivered transactions in 2019 or 2020.
- Total weight of transactions per year for each country of departure.
- Drivers who drove vessels to Spain and to Turkey.