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The tuple calculus
In databases we use a declarative query language:
- looks “like” logic and set expressions
- in databases we use a different syntax
- we translate natural language to tuple calculus expressions and back
Notes:
The main declarative query language we use in the course Databases 1 is the tuple calculus. This is a language that looks similar to the expression language used in the course on logic and set theory (2IT10).
In databases we use a different syntax. This requires you to do a bit of conversion in your mind, but dealing with different syntaxes for things that mean essentially the same is just a fact of life in computer science.
Since the tuple calculus for databases means essentially the same as the expressions in the course on logic and set theory it is vital that you master the logic and set theory concepts and language. If you did not yet pass that course or an equivalent course it is very likely that you will fail the course Databases 1.
In the first labsession we will first write some database queries using the plain logic and set theory expressions. In a later labsession we will start using the real tuple calculus.
We will have a large number of exercises to make you acquainted with this new language, but conceptually you should in fact already master it, except for the small syntactic differences.