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JPA EntityManager: Why use persist() over merge()?
...ed (any changes you make will not be part of the transaction - unless you call merge again). You can through use returned instance (managed one).
Maybe a code example will help.
MyEntity e = new MyEntity();
// scenario 1
// tran starts
em.persist(e);
e.setSomeField(someValue);
// tran ends, an...
How to open in default browser in C#
I am designing a small C# application and there is a web browser in it. I currently have all of my defaults on my computer say google chrome is my default browser, yet when I click a link in my application to open in a new window, it opens internet explorer. Is there any way to make these links open...
Is JavaScript an untyped language?
I've found that some people call JavaScript a "dynamically, weakly typed" language, but some even say "untyped"? Which is it really?
...
How do browser cookie domains work?
...e's domain attribute is set,
the cookie is applicable to that domain and all its subdomains;
the cookie's domain must be the same as, or a parent of, the origin domain
the cookie's domain must not be a TLD, a public suffix, or a parent of a public suffix.
It can be derived that a cookie is alwa...
How do I get Windows to go as fast as Linux for compiling C++?
...for Linux. This might result in unnecessary compilations when you make a small change. You might be able to validate this using the same compiler toolchain on Windows.
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Why do you program in assembly? [closed]
I have a question for all the hardcore low level hackers out there. I ran across this sentence in a blog. I don't really think the source matters (it's Haack if you really care) because it seems to be a common statement.
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How can I concatenate NSAttributedStrings?
...
NSMutableAttributedString *mutableAttString = [[NSMutableAttributedString alloc] init];
NSString *plainString = // ...
NSDictionary *attributes = // ... a dictionary with your attributes.
NSAttributedString *newAttString = [[NSAttributedString alloc] initWithString:plainString attributes:attribute...
How do I drag and drop files into an application?
...orm1 : Form {
public Form1() {
InitializeComponent();
this.AllowDrop = true;
this.DragEnter += new DragEventHandler(Form1_DragEnter);
this.DragDrop += new DragEventHandler(Form1_DragDrop);
}
void Form1_DragEnter(object sender, DragEventArgs e) {
if (e.Data....
Can a foreign key be NULL and/or duplicate?
...at field must exist first in a different table (the parent table). That is all an FK is by definition. Null by definition is not a value. Null means that we do not yet know what the value is.
Let me give you a real life example. Suppose you have a database that stores sales proposals. Suppose furth...
Proper way to rename solution (and directories) in Visual Studio
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Manually edit .sln file
This method is entirely aimed at renaming the directory for the project, as viewed in Windows Explorer.
This method does not suffer from the problems in the Remove/add project file method below (referenc...