Things I wished more developers knew about databases

Re:Things I wished more developers knew about databases by taffer on Thursday April 23, 2020 @04:15AM (#22953825)

> I don't see how JOIN is like flatMap

This is explained in the blog post I linked, including an example.

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Re:Things I wished more developers knew about databases by karmakaze on Thursday April 23, 2020 @03:38PM (#22960229)

It's really flatMap/map from the link:

  List<Integer> s1 = Stream.of(1, 2);
  Supplier<Stream<String>> s2 = ()->Stream.of("A", "B");

  s1.flatMap(v1 -> s2.get()
                   .map(v2 -> tuple(v1, v2)))
    .forEach(System.out::println);

That's just a nested loop.

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