select(::Table, ::Pair{Tuple, Tuple})

[shashi]

julia> t
x  y   │ color    size
───────┼──────────────
1  "a" │ "red"    15
2  "b" │ "green"  10
3  "c" │ "blue"   5

julia> select(t, (:color,:size) => (:y,))
color    size │ y
──────────────┼────
"blue"   5    │ "c"
"green"  10   │ "b"
"red"    15   │ "a"

julia> select(t, (:color,:x))
3-element IndexedTables.Columns{NamedTuples._NT_color_x{String,Int64},NamedTuples._NT_color_x{Array{String,1},Array{Int64,1}}}:
 (color = "red", x = 1)  
 (color = "green", x = 2)
 (color = "blue", x = 3) 

julia> select(t, (2,3)=>(1,4))
─────────────┬──────
"a"  "red"   │ 1  15
"b"  "green" │ 2  10
"c"  "blue"  │ 3  5

julia> select(t, (2,3)=>(as(:x, :id), as(x->15-x, :size, :invsize)))
             │ id  invsize
─────────────┼────────────
"a"  "red"   │ 1   0
"b"  "green" │ 2   5
"c"  "blue"  │ 3   10

[davidanthoff]

Very cool, I think we are getting very close to be able to create some custom Query.jl backends for IndexedTable and JuliaDB that give the normal Query.jl user API with the much improved performance of these types here. Very exciting!!

[codecov-io]

Codecov Report

Merging #55 into master will decrease coverage by 0.54%.
The diff coverage is 79.54%.

@@            Coverage Diff             @@
##           master      #55      +/-   ##
==========================================
- Coverage   93.49%   92.94%   -0.55%     
==========================================
  Files           6        6              
  Lines         922      964      +42     
==========================================
+ Hits          862      896      +34     
- Misses         60       68       +8

Impacted Files	Coverage Δ
src/columns.jl	95.45% <100%> (+0.1%)	⬆️
src/IndexedTables.jl	91.96% <50%> (-3.23%)	⬇️
src/utils.jl	97.47% <66.66%> (-0.8%)	⬇️
src/join.jl	88.8% <75%> (+0.09%)	⬆️
src/query.jl	94.93% <88.46%> (-0.8%)	⬇️

---

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