In parts 1 and 2 we defined our core query types and figured out how to insert into the database. Here, we'll actually write some queries. We're going to port the professional hitmen example from William Yao's which type-safe database library should you use blog post to Databass and see how it stacks up.
Welcome to Databass, Part 2, even more bass. In part 1, we defined a query GADT and runQuery function. Here, we'll figure out how to materialize relations and tuples in memory. As before, full source is on github. First, though, I had a question about implementing Group and Ungroup, which we skipped in part 1.
It's been a while since my last language series on this blog, but I figured I shouldn't let an entire calendar year go by without doing some technical writing here. This time we'll be working on creating a toy relational database in the vein of Tutorial D, as described in Databases, Types, and The Relational Model: The Third Manifesto by C.