RosettaCodeData/Task/Hash-join/Julia/hash-join-2.julia

20 lines
529 B
Plaintext

function hashjoin(A::Array, ja::Int, B::Array, jb::Int)
M = Dict(t[jb] => filter(l -> l[jb] == t[jb], B) for t in B)
return collect([a, b] for a in A for b in get(M, a[ja], ()))
end
table1 = [(27, "Jonah"),
(18, "Alan"),
(28, "Glory"),
(18, "Popeye"),
(28, "Alan")]
table2 = [("Jonah", "Whales"),
("Jonah", "Spiders"),
("Alan", "Ghosts"),
("Alan", "Zombies"),
("Glory", "Buffy")]
for r in hashjoin(table1, 2, table2, 1)
println(r)
end