DB RelationalAlgebra

A native iPad and iPhone app that converts a SQL query typed, pasted, or imported from a .sql file into relational algebra, tuple relational calculus and domain relational calculus. Each notation gets a step by step derivation, a final oneline formula, and an interactive diagram an operator tree for the algebra, a quantifier scope tree for the calculus and a fourth view stacks all three against the same query. Whatever SQL asks for that a notation cannot express exactly is reported rather than quietly approximated.