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How can I select rows with most recent timestamp for each key value?
...ensorID, timestamp;
Pretty self-explaining I think, but here's more info if you wish, as well as other examples. It's from the MySQL manual, but above query works with every RDBMS (implementing the sql'92 standard).
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How to have Emacs auto-refresh all buffers when files have changed on disk?
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@Dave: (global-)auto-reverse-mode will not revert a file if the corresponding buffer is modified, so there should be no risk of you losing unsaved changes.
– Lindydancer
Mar 4 '12 at 15:23
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How do I change the default author and committer in the Eclipse Git plugin?
...name of user>"
git config --global user.email "<email of user>"
If you want to change the author of an existing commit, look here
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What is the difference between an ordered and a sorted collection?
Is there any difference between a sorted and an ordered collection?
8 Answers
8
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How to disable CSS in Browser for testing purposes
...s
Alternatively with the developer toolbar enabled you can press Alt+Shift+A.
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Why is a “GRANT USAGE” created the first time I grant a user privileges?
... privileges". From the MySQL Reference Manual:
The USAGE privilege specifier stands for "no privileges." It is used at the global level with GRANT to modify account attributes such as resource limits or SSL characteristics without affecting existing account privileges.
USAGE is a way to tell ...
Scala @ operator
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o match {
case Some(x) => println(x)
case None =>
}
But what if you wanted not the content of Some, but the option itself? That would be accomplished with this:
o match {
case x @ Some(_) => println(x)
case None =>
}
Note that @ can be used at any level, not just at the to...
What is the maximum number of characters that nvarchar(MAX) will hold?
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@quakkels: use VARCHAR(MAX), if you don't need the 2-byte support for Asian, Arab or Cyrillic languages. Use (N)VARCHAR(x) if you know a string will never be longer than x characters (don't use NVARCHAR(MAX) for a first name - use NVARCHAR(50) or whateve...
Return first match of Ruby regex
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If only an existence of a match is important, you can go with
/regexp/ =~ "string"
Either way, match should only return the first hit, while scan searches throughout entire string. Therefore if
matchData = "string strin...
What is the use of “ref” for reference-type variables in C#?
I understand that if I pass a value-type ( int , struct , etc.) as a parameter (without the ref keyword), a copy of that variable is passed to the method, but if I use the ref keyword a reference to that variable is passed, not a new one.
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