大约有 6,300 项符合查询结果（耗时：0.0190秒） [XML]
Is there any difference between GROUP BY and DISTINCT
I learned something simple about SQL the other day:
26 Answers
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VIM ctrlp.vim plugin: how to rescan files?
I have come across the awesome ctrlp.vim plugin . It is a good alternative to the Command-T plugin which I have used before. What I did not like about Command-T is that it would take about 20-30 seconds to rescan files when it is invoked for the first time after starting vim.
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How to count string occurrence in string?
How can I count the number of times a particular string occurs in another string. For example, this is what I am trying to do in Javascript:
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Looking for a clear definition of what a “tokenizer”, “parser” and...
I am looking for a clear definition of what a "tokenizer", "parser" and "lexer" are and how they are related to each other (e.g., does a parser use a tokenizer or vice versa)? I need to create a program will go through c/h source files to extract data declaration and definitions.
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curl -GET and -X GET
...lso offers the same methods without. I've tried both and I can't seem to figure out the difference. Can someone explain to me quickly how these two operations differ?
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How to find all duplicate from a List? [duplicate]
I have a List<string> which has some words duplicated. I need to find all words which are duplicates.
9 Answers
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Counting the number of elements with the values of x in a vector
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You can just use table():
> a <- table(numbers)
> a
numbers
4 5 23 34 43 54 56 65 67 324 435 453 456 567 657
2 1 2 2 1 1 2 1 2 1 3 1 1 1 1
Then you can subset it:
> a[names(a)==435]
435
3
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How to paste yanked text into the Vim command line
..., use Ctrl-R, Ctrl-O, ".
Here is an explanation of what you can do with registers. What you can do with registers is extraordinary, and once you know how to use them you cannot live without them.
Registers are basically storage locations for strings. Vim has many registers that work in different w...
How to make Regular expression into non-greedy?
I'm using jQuery. I have a string with a block of special characters (begin and end). I want get the text from that special characters block. I used a regular expression object for in-string finding. But how can I tell jQuery to find multiple results when have two special character or more?
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In C#, What is a monad?
... is a lot of talk about monads these days. I have read a few articles / blog posts, but I can't go far enough with their examples to fully grasp the concept. The reason is that monads are a functional language concept, and thus the examples are in languages I haven't worked with (since I haven't use...