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How to join (merge) data frames (inner, outer, left, right)
...s these operations in SQL.
library(sqldf)
## inner join
df3 <- sqldf("SELECT CustomerId, Product, State
FROM df1
JOIN df2 USING(CustomerID)")
## left join (substitute 'right' for right join)
df4 <- sqldf("SELECT CustomerId, Product, State
FROM df1...
Kill child process when parent process is killed
I'm creating new processes using System.Diagnostics.Process class from my application. I want this processes to be killed when/if my application has crashed. But if I kill my application from Task Manager, child processes are not killed. Is there any way to make child processes dependent on ...
How to set breakpoints in inline Javascript in Google Chrome?
...e directory tree underneath it (with the up and down arrow in it), you can select the file you want to debug. You can get out of an error by pressing resume on the right-hand side of the same tab.
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What is the correct way to get a subarray in Scala?
...irst n elements with take(n: Int)
array.take(4) // Array('a','b','c','d')
Select any interval of elements with slice(from: Int, until: Int). Note that until is excluded.
array.slice(2,4) // Array('c','d')
The slice method is stricly equivalent to:
array.take(4).drop(2) // Array('c','d')
Exclude t...
How to downgrade or install an older version of Cocoapods
...e default version, so you have to sudo gem uninstall cocoapods first, then select 1.0.0 as the version to remove. Not sure if this has always been the behavior, but sudo gem install cocoapods -v 0.39.0 alone didn't do the trick for me once I had 1.0.0.
– fullofsquirrels
...
MySQL: Sort GROUP_CONCAT values
... see http://dev.mysql.com/doc/refman/...tions.html#function_group-concat:
SELECT student_name,
GROUP_CONCAT(DISTINCT test_score ORDER BY test_score DESC SEPARATOR ' ')
FROM student
GROUP BY student_name;
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Loop through files in a folder using VBA?
...2 Then
FileExtStr = ".xls": FileFormatNum = -4143
Else
Select Case xWb.FileFormat
Case 51:
FileExtStr = ".xlsx": FileFormatNum = 51
Case 52:
If Application.ActiveWorkbook.HasVBProject Then
FileExtStr = "....
When to Redis? When to MongoDB? [closed]
...e, writing stupid sql statements... not just one but freaking everywhere. "select this, select that". But in particular you remember the irritating WHERE clause. Where lastname equals "thornton" and movie equals "bad santa." Urgh. You think, "why don’t those dbas just do their job and give me som...
成功熬了四年还没死？一个IT屌丝创业者的深刻反思 - 资讯 - 清泛网 - 专注C...
...升级为Nginx，在Mac上装Ubuntu，Ubuntu里再装个虚拟机去跑Mac OS……
IT青年们也喜欢升级自己的人生，从程序员升级到项目经理，再升级到技术总监或产品总监，再升级到合伙人……
在不断追求升级的过程中，所面临的一个很...
What's the difference between “git reset” and “git checkout”?
.... git checkout is about updating the working tree and switching currently "selected" branch (the HEAD).
– Mikko Rantalainen
Dec 9 '13 at 11:02
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