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CREATE TABLE R(X INT, Y INT); CREATE TABLE S(Y INT, Z INT); CREATE TABLE T(Z INT, Y INT); CREATE TABLE TT(Z INT, Y INT); INSERT INTO R(X,Y) VALUES (1,1),(2,2),(3,3),(4,3),(5,5); INSERT INTO S(Y,Z) VALUES (1,1),(2,1),(3,4),(3,5),(5,6); INSERT INTO T(Z,Y) VALUES (1,1),(1,2),(4,3),(5,3),(6,5); INSERT INTO TT(Z,Y) VALUES (1,1),(1,2),(4,3),(5,3),(6,5); CREATE VIEW ANSWERS(X,Y,Z) AS SELECT R.X, R.Y, S.Z FROM R JOIN S ON S.Y=R.Y JOIN T ON T.Z=S.Z JOIN TT IN TT.Z=S.Z; SELECT * FROM ANSWERS;