ufeanei
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| class Octal | |
| attr_accessor :octnum | |
| def initialize(num) | |
| @octnum = num | |
| end | |
| def not_valid? | |
| octnum == '0' || octnum =~ /[A-Fa-f8-9]/ | |
| end |
ufeanei
/ gist:53255767d3664a0904c898d08518426e
Last active
September 11, 2021 20:37
Mongo aggregation grouping by categories then grouping by subcategories
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| consider the collection shown below | |
| [ | |
| { | |
| _id: 1, | |
| category: "A", | |
| subCategory: "a1", | |
| }, | |
| { |