Tugas Basdat - Aljabar Relasi (Ricky Ayu Tsuraya - j1f112022) [PDF]

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Nama : Ricky Ayu Tsuraya NIM : J1F112022



1. Cari nama-nama sailor yang memesan boat 103



πsname ((σbid=103 Reserves) | x | Sailors) SELECT * FROM Sailors, Reserves WHERE Sailors.sid = Reserves.sid AND Reserves.bid = 103 2. Cari nama-nama sailor yang memesan boat warna merah



πsname ((σcolor=Red Reserves) | x | Sailors) SELECT S.sname FROM Sailors S, Reserves R, Boats B WHERE S.sid = R.sid AND R.bid = B.bid AND B.color = ‘red’ 3. Cari warna dari boat yang dipesan oleh Lubber



πcolor ((σsname=”Lubber” Sailors) | x | Reserves | x | Boats) SELECT B.color FROM Boats B, Sailors S, Reserves R WHERE S.sid = R.sid AND R.bid = B.bid AND S.sname = ‘Lubber’ 4. Cari nama-nama sailor yang memesan paling sedikit satu boat



πsname (Sailors| x | Reserves) SELECT sname FROM Sailors S, Reserves R WHERE S.sid = R.sid 5. Cari nama-nama sailor yang memesan boat warna merah atau hijau



Ρ(TemBoats,(σcolor-‘red’Boats)  (σcolor-‘green’ Boats)) πsname(TempBoats | x | Reserves | x | Sailors) SELECT R.sid FROM Boats B, Reserves R WHERE R.bid = B.bid AND B.color = ‘red’ UNION SELECT R2.sid



FROM Boats B2, Reserves R2 WHERE R2.bid = B2.bid and B2.color = ‘green’ 6. Cari sid dari sailor yang berumur lebih dari 20 tahun yang tidak memesan boat warna merah



πsid(σage>20 Sailors) - πsid((σcolor-‘red’Boats) | x | Reserves | x | Sailors) SELECT sid FROM (Sailors join Reserves join Boats) WHERE (age>20 AND color is not ‘red’)