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ORA-30926: unable to get a stable set of rows in the source tables
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This is usually caused by duplicates in the query specified in USING clause. This probably means that TABLE_A is a parent table and the same ROWID is returned several times.
You could quickly solve the problem by using a DISTINCT in your query (in fact, if 'Y' is a constant val...
How do I test a file upload in rails?
...ls 3, Rails 5), which will search your fixtures directory for the file specified and will make it available as a test file for the controller in functional testing. To use it:
1) Put your file to be uploaded in the test in your fixtures/files subdirectory for testing.
2) In your unit test you can ...
How can I check if the current date/time is past a set date/time?
...r, if you are using UTC dates (as you should), prefer to use new DateTime("now", new DateTimeZone('UTC')). This will prevent your app from misunderstandable bugs in dates. i advise you to store it in a function static variable, a class static or somewhere else in your running process...
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multiple prints on the same line in Python
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This doesn't work if you have both prints and a time consuming action in between (all in the same function / indentation level). Before the action starts, there is no output at all and after it is finished the output appears as whole
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std::unique_lock or std::lock_guard?
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The difference is that you can lock and unlock a std::unique_lock. std::lock_guard will be locked only once on construction and unlocked on destruction.
So for use case B you definitely need a std::unique_lock for the condition v...
What ReSharper 4+ live templates for C# do you use? [closed]
...essFinalize(this);
}
protected virtual void Dispose(bool disposing)
{
if (!disposed)
{
if (disposing)
{
if ($MEMBER$ != null)
{
$MEMBER$.Dispose();
$MEMBER$ = null;
}
}
disposed = true;
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LINQ Join with Multiple Conditions in On Clause
...tID == x.ProjectID && x.Completed == true)
.DefaultIfEmpty()
select new { t1.ProjectName, t2.TaskName }
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Constantly print Subprocess output while process is running
...d stdout_line
popen.stdout.close()
return_code = popen.wait()
if return_code:
raise subprocess.CalledProcessError(return_code, cmd)
# Example
for path in execute(["locate", "a"]):
print(path, end="")
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What's the difference between assignment operator and copy constructor?
I don't understand the difference between assignment constructor and copy constructor in C++. It is like this:
8 Answers
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How many threads can a Java VM support?
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I know this question is pretty old but just want to share my findings.
My laptop is able to handle program which spawns 25,000 threads and all those threads write some data in MySql database at regular interval of 2 seconds.
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