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What's wrong with nullable columns in composite primary keys?
...ow in a table: when a table has a primary key, you have a guranteed way to select any row from it.
A unique constraint does not necessarily identify every row; it just specifies that if a row has values in its columns, then they must be unique. This is not sufficient to uniquely identify every row...
Maven plugins can not be found in IntelliJ
...le artifacts. This can be done in "Settings > Maven > Repositories", select there your "Local" and simply click "Update".
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How to delete a file from SD card?
...
File file = new File(selectedFilePath);
boolean deleted = file.delete();
where selectedFilePath is the path of the file you want to delete - for example:
/sdcard/YourCustomDirectory/ExampleFile.mp3
...
Detecting Browser Autofill
...e change event.
Firefox 4 does dispatch the change change event when users select a value from a list of suggestions and tab out of the field.
Chrome 9 does not dispatch the change event.
Safari 5 does dispatch the change event.
You best options are to either disable autocomplete for a form usin...
Is it possible to embed animated GIFs in PDFs?
...mes by making a fake loop.
Open the Gif in Photoshop
View the timeline
Select all the instances and duplicate them (I did it 10 times)
Export as a MP4
Open up your PDF and go to TOOLS> RICH MEDIA>ADD VIDEO> then place the video of your gif where you would want it
A window comes up, be s...
How to access random item in list?
... isn't repeated? Let's say I wanted to shuffle a deck of cards by randomly selecting one at a time, but obviously can't select the same card twice.
– AdamMc331
Sep 21 '14 at 5:26
7...
C++常用排序算法汇总 - C/C++ - 清泛网 - 专注C/C++及内核技术
...汇总sort_algorithm介绍了C++常用的几种排序算法：选择排序(SelectSort)，冒泡排序(BubbleSort)，快速排序(QuickSort)，归并排序(MergeSort)，堆排序(HeapSort)，插入排序(InsertSort)，希尔排序(ShellSort) 1、选择排序(SelectSort)
/************************...
How to use a switch case 'or' in PHP
...le switch(), and when I'm working in a C-ish language I really miss having Select Case, which is really a shorthand way of saying "there's a big block of if, else if, else-if... here".
– Stan Rogers
Oct 9 '10 at 7:50
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Improving bulk insert performance in Entity framework [duplicate]
... {
var e = entity;
table.Rows.Add(properties.Select(property => GetPropertyValue(property.GetValue(e, null))).ToArray());
}
// send it to the server for bulk execution
bulkCopy.BulkCopyTimeout = 5 * 60;
bulkCopy.WriteToServer(table);
...
Is there a way to do repetitive tasks at intervals?
...(5 * time.Second)
quit := make(chan struct{})
go func() {
for {
select {
case <- ticker.C:
// do stuff
case <- quit:
ticker.Stop()
return
}
}
}()
You can stop the worker by closing the quit channel: close(quit).
...