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Why doesn't c++ have &&= or ||= for booleans?
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all the more reason to have &&= in my opinion. =P
– Kache
Mar 21 '10 at 20:19
4
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ERROR 1452: Cannot add or update a child row: a foreign key constraint fails
...2. Cannot add or update a child row: a foreign key constraint fails essentially means that, you are trying to add a row to your Ordrelinje table for which no matching row (OrderID) is present in Ordre table.
You must first insert the row to your Ordre table.
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What is the difference between JOIN and JOIN FETCH when using JPA and Hibernate
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In this two queries, you are using JOIN to query all employees that have at least one department associated.
But, the difference is: in the first query you are returning only the Employes for the Hibernate. In the second query, you are returning the Employes and all Depart...
What is meant by immutable?
... without worrying that someone else is going to change its contents. Especially when dealing with concurrency, there are no locking issues with objects that never change
e.g.
class Foo
{
private final String myvar;
public Foo(final String initialValue)
{
this.myvar = initi...
How to determine the first and last iteration in a foreach loop?
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@Twan How is point #3 right? Or relevant at all to this question since it involves HTML? This is a PHP question, clearly... and when it comes to mark-up semantics, it's down to a much deeper facts than "a proper blahblah is always better than blahblah (this is not even...
Should I call Close() or Dispose() for stream objects?
... StreamWriter etc implements IDisposable interface. That means, we can call Dispose() method on objects of these classes. They've also defined a public method called Close() . Now that confuses me, as to what should I call once I'm done with objects? What if I call both?
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SignalR: Why choose Hub vs. Persistent Connection?
...persistent connections.
From the highly up-voted comment below:
Partially correct. You can get topics or groups in persistent connections as well. The big difference is dispatching different types of messages. For example you have different kinds of messages and you want to send different kind...
Failed to enable constraints. One or more rows contain values violating non-null, unique, or foreign
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This problem is usually caused by one of the following
null values being returned for columns not set to AllowDBNull
duplicate rows being returned with the same primary key.
a mismatch in column definition (e.g. size of char fields) between t...
What is the exact problem with multiple inheritance?
I can see people asking all the time whether multiple inheritance should be included into the next version of C# or Java. C++ folks, who are fortunate enough to have this ability, say that this is like giving someone a rope to eventually hang themselves.
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How do I find the most recent git commit that modified a file?
...ts looking at the history of specific files (and directories), so you can call it like this:
git log my/file.c
If you really only want to list the one most recent commit, for example to use it in a script, use the -n 1 option:
git log -n 1 --pretty=format:%H -- my/file.c
--pretty=format:%h tel...