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π Nome.Empregado (σ Empregado.IdentEmp = TrabalhoNo.IdentEmp ^
TrabalhaNo.ProjNum = Projeto.ProjNum ^
Nome = ‘Banco de Dados’ ((Empregado x TrabalhoNo) x Projeto))
More specifically in the part I make a Cartesian product "triple" ((Employee X Work) x Project)). It is possible?
But do Mysql or Oracle implement relational algebra? Nothing prevents the Cartesian product from involving more than two relations.
– anonimo
I don’t think so; I didn’t have a tag for relational algebra and I couldn’t create the tag because of my reputation.
– Paulo