大约有 40,000 项符合查询结果（耗时：0.0604秒） [XML]
How can I select rows with most recent timestamp for each key value?
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For the sake of completeness, here's another possible solution:
SELECT sensorID,timestamp,sensorField1,sensorField2
FROM sensorTable s1
WHERE timestamp = (SELECT MAX(timestamp) FROM sensorTable s2 WHERE s1.sensorID = s2.sensorID)
ORDER BY ...
Left-pad printf with spaces
...ot I think a constant with 40 spaces would be faster. I don't know if the compiler is able to optimize printf formats.
– Bill the Lizard
Nov 16 '08 at 4:13
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MIN/MAX vs ORDER BY and LIMIT
... edited May 23 '17 at 12:02
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answered Jan 9 '09 at 1:51
Sean McSomethingSean ...
.NET JIT potential error?
... Just Visual Studio, copy/paste from the debugger's Disassembly window and comments added by hand.
– Hans Passant
May 23 '13 at 16:19
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Multiple columns index when using the declarative ORM extension of sqlalchemy
According to the documentation and the comments in the sqlalchemy.Column class, we should use the class sqlalchemy.schema.Index to specify an index that contains multiple columns.
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Difference between Select and ConvertAll in C#
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You can't compare Select and ConvertAll. The former selects every item in a sequence and you're free to do whatever you want with it. The latter has a clear intention: convert this item to something else.
– Tim S...
Naming convention for Scala constants?
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The officially recommended style (and I do mean officially) is the first style, camel case with first letter are upper case. It's laid down clearly by Odersky on Programming in Scala.
The style is also followed by the standard library, and h...
Who is “us” and who is “them” according to Git?
...ut when only one branch is involved, such as when re-ordering or squashing commits during a rebase?
– Justin Johnson
Sep 10 '16 at 0:55
14
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How can I use different certificates on specific connections?
...dule I'm adding to our large Java application has to converse with another company's SSL-secured website. The problem is that the site uses a self-signed certificate. I have a copy of the certificate to verify that I'm not encountering a man-in-the-middle attack, and I need to incorporate this cer...
Passing a String by Reference in Java?
... time. In fact when you write Java code like s = "Hello " + name, then the compiler will generate byte code which creates a StringBuilder and calls append() two times.
– Aaron Digulla
May 7 '19 at 13:36
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