大约有 47,000 项符合查询结果(耗时:0.0570秒) [XML]
Multiple INSERT statements vs. single INSERT with multiple VALUES
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I thought I'd look into this a bit more though so set up a loop (script) and tried adjusting the number of VALUES clauses and recording the compile time.
I then divided the compile time by the number of rows to get the average compile time per clause. The results are below
Up until 250 VALUES ...
How to export query result to csv in Oracle SQL Developer?
...wn as Method 1 below:
Method 1
Add the comment /*csv*/ to your SQL query and run the query as a script (using F5 or the 2nd execution button on the worksheet toolbar)
That's it.
Method 2
Run a query
Right click and select unload.
Update. In Sql Developer Version 3.0.04 unload has been ch...
Format date in a specific timezone
I'm using Moment.js to parse and format dates in my web app. As part of a JSON object, my backend server sends dates as a number of milliseconds from the UTC epoch (Unix offset).
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Is AngularJS just for single-page applications (SPAs)?
...ooking at options to build the front end of an application we are creating and are trying to evaluate a tool that will work for us and give us the best platform to move forward.
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How can I trim leading and trailing white space?
I am having some troubles with leading and trailing white space in a data.frame.
13 Answers
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Delete last commit in bitbucket
I made a mistake and I don't know how to delete my latest push in the repository. I pull the latest updates of the app but it has conflicts and I push it to repository.
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Cluster analysis in R: determine the optimal number of clusters
..., calinski.best, "\n")
# 5 clusters!
Four. Determine the optimal model and number of clusters according to the Bayesian Information Criterion for expectation-maximization, initialized by hierarchical clustering for parameterized Gaussian mixture models
# See http://www.jstatsoft.org/v18/i06/pap...
The tilde operator in C
I've seen the tilde operator used in the ELF hashing algorithm, and I'm curious what it does. (The code is from Eternally Confused .)
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Is using 'var' to declare variables optional? [duplicate]
...use var). If you use var in the global scope, the variable is truly global and cannot be deleted.
This is, in my opinion, one of the most dangerous issues with javascript, and should be deprecated, or at least raise warnings over warnings. The reason is, it's easy to forget var and have by accident...
How do I install Python OpenCV through Conda?
...to import cv2.cv (am I missing something obvious?)
– Andy Hayden
Aug 13 '15 at 5:03
2
This works ...