Question

Using the sports database containing two relations

(TEAM, MATCH_DETAILS), answer the following

relational algebra queries.

a) Retrieve the MatchID of all those matches where both

the teams have scored > 70.

b) Retrieve the MatchID of all those matches where

FirstTeam has scored < 70 but SecondTeam has

scored > 70.

c) Find out the MatchID and date of matches played by

Team 1 and won by it.

d) Find out the MatchID of matches played by Team 2

and not won by it.

e) In the TEAM relation, change the name of the relation

to T_DATA. Also change the attributes TeamID and

TeamName to T_ID and T_NAME respectively​

Answer 1

Answer:

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Answer 2

--  Retrieve the MatchID of all those matches where both the teams have scored > 70

select Match_id

from March_details

where First_team_score >70 and Second_team_score >70;

-- Retrieve the MatchID of all those matches where FirstTeam has scored < 70 but SecondTeam has scored > 70

select Match_id

from March_details

where First_team_score <70 and Second_team_score >70;

--  Find out the MatchID and date of matches played by Team 1 and won by it

select Match_id, March_date

from March_details

where First_team_score>Second_team_score and First_team_id=1

union

select Match_id, March_date

from March_details

where Second_team_score> First_team_score and Second_team_id =1 ;

-- Find out the MatchID of matches played by Team 2 and not won by it.

select Match_id

from March_details

where First_team_id=2 and First_team_score < Second_team_score

union

select Match_id

from March_details

where Second_team_id=2 and First_team_score > Second_team_score ;

-- In the TEAM relation, change the name of the relation to T_DATA. Also change the attributes TeamID and TeamName to T_ID and T_NAME respectively

select Team_id as T_ID, Team_name as T_NAME

from team as T_DATA;