大约有 41,400 项符合查询结果（耗时：0.0446秒） [XML]
Pandas count(distinct) equivalent
...ple:
In [2]: table
Out[2]:
CLIENTCODE YEARMONTH
0 1 201301
1 1 201301
2 2 201301
3 1 201302
4 2 201302
5 2 201302
6 3 201302
In [3]: table.groupby('YEARMONTH').CLIENTCODE.nunique()
Out[3]:
YEARM...
How can I see the SQL that will be generated by a given ActiveRecord query in Ruby on Rails
...eir queries directly. It is private API so there is a huge risk that Rails 3 will totally break it, but for debugging, it is an ok solution.
The method is construct_finder_sql(options) (lib/active_record/base.rb:1681) you will have to use send because it is private.
Edit: construct_finder_sql was...
Rails: Is there a rails trick to adding commas to large numbers?
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354
You want the number_with_delimiter method. For example:
<%= number_with_delimiter(@number,...
What is the leading LINQ for JavaScript library? [closed]
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13
Have you seen Rx for Javascript, yet? That's what you want.
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Flatten an irregular list of lists
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390
Using generator functions can make your example a little easier to read and probably boost the...
Why did Rails4 drop support for “assets” group in the Gemfile
In Rails 3, gems used exclusively to generate assets in the asset pipeline were properly placed in the assets group of the Gemfile:
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Using multiple delimiters in awk
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333
The delimiter can be a regular expression.
awk -F'[/=]' '{print $3 "\t" $5 "\t" $8}' file
P...
Which UUID version to use?
...eed to always generate the same UUID from a given name, you want a version 3 or version 5.
Version 3: This generates a unique ID from an MD5 hash of a namespace and name. If you need backwards compatibility (with another system that generates UUIDs from names), use this.
Version 5: This generates ...
Can I have multiple :before pseudo-elements for the same element?
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