大约有 47,000 项符合查询结果(耗时:0.0712秒) [XML]
SQL WHERE ID IN (id1, id2, …, idn)
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Option 3 is simply horrible performance-wise. It sends a query every loop and hammers the database with small queries. It also prevents it from using any optimizations for "value is one of those in a given list"
share
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range over interface{} which stores a slice
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Well I used reflect.ValueOf and then if it is a slice you can call Len() and Index() on the value to get the len of the slice and element at an index. I don't think you will be able to use the range operate to do this.
package main
import "fmt"
import...
How to check if a file contains a specific string using Bash
...ns # SomeString was found
fi
You don't need [[ ]] here. Just run the command directly. Add -q option when you don't need the string displayed when it was found.
The grep command returns 0 or 1 in the exit code depending on
the result of search. 0 if something was found; 1 otherwise.
$ echo hello...
How to put an image in div with CSS?
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This answer by Jaap :
<div class="image"></div>
and in CSS :
div.image {
content:url(http://placehold.it/350x150);
}
you can try it on this link :
http://jsfiddle.net/XAh2d/
this is a link about css content
http://css-tricks.com/css-content/
This has been teste...
Linux find file names with given string
I'm on Ubuntu, and I'd like to find all files in the current directory and subdirectories whose name contains the string "John". I know that grep can match the content in the files, but I have no idea how to use it with file names. Any help would be appreciated.
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What is copy-on-write?
I would like to know what copy-on-write is and what it is used for? The term 'copy-on-write array' is mentioned several times in the Sun JDK tutorials but I didn't understand what it meant.
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composer: How to find the exact version of a package?
...ut...
composer.phar show
Will show all the currently installed packages and their version information. (This was shown in previous versions of Composer only when using the now-deprecated -i option.)
To see more details, specify the name of the package as well:
composer.phar show monolog/monolo...
CUDA incompatible with my gcc version
... with CUDA SDK.
I have installed the developers driver (version 270.41.19) and the CUDA toolkit,
then finally the SDK (both the 4.0.17 version).
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Should import statements always be at the top of a module?
...an prevent circular dependencies.
For example, if you have 2 modules, X.py and Y.py, and they both need to import each other, this will cause a circular dependency when you import one of the modules causing an infinite loop. If you move the import statement in one of the modules then it won't try to...
How do you prevent IDisposable from spreading to all your classes?
...ble from spreading. Some classes need to be disposed, like AutoResetEvent, and the most efficient way is to do it in the Dispose() method to avoid the overhead of finalizers. But this method must be called somehow, so exactly as in your example the classes that encapsulate or contain IDisposable hav...