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What is the use of having destructor as private?
... has been "friend"ed) responsible for counting the number of references to itself and delete it when the number hits zero. A private dtor would prevent anybody else from deleting it when there were still references to it.
For another instance, what if you have an object that has a manager (or itse...
Checking for empty queryset in Django
...fer to has for contract to raise 404 if the filtering expression does not hit any records or to produce a list of the result if there are records. The code there will hit the database just once. If they used exist() or count() to first check whether there are going to be records returned, they'd be ...
How to use the IEqualityComparer
I have some bells in my database with the same number. I want to get all of them without duplication. I created a compare class to do this work, but the execution of the function causes a big delay from the function without distinct, from 0.6 sec to 3.2 sec!
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How to generate JAXB classes from XSD?
I'm a total newbie with XML. I'm doing a Java EE project REST implementation and we return a lot of XML. With this we decided to use JAXB. So far, we manually coded the Models for the XML.
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javac : command not found
...include javac.
By the way: you can find out which package provides javac with a yum search, e.g.
su -c 'yum provides javac'
on more recent releases of CentOS e.g. 6 the command changes to
su -c 'yum provides */javac'
Another note: using yum and openjdk is only one possibility to install the J...
SQL Add foreign key to existing column
...I am using the following SQL command in SQL Server 2008 to update a table with a foreign key constraint:
6 Answers
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How to make MySQL handle UTF-8 properly
...sure my database can handle UTF-8 characters correctly. How I can do this with MySQL?
14 Answers
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Best way to select random rows PostgreSQL
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Given your specifications (plus additional info in the comments),
You have a numeric ID column (integer numbers) with only few (or moderately few) gaps.
Obviously no or few write operations.
Your ID column has to be indexed! A primary key serves nicely.
Th...
Is there a “goto” statement in bash?
Is there a "goto" statement in bash ? I know It is considered bad practice, but I need specifically "goto".
12 Answers
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How to print SQL statement in codeigniter model
...m of your pages.
To enable the profiler place the following line anywhere within your Controller methods:
$this->output->enable_profiler(TRUE);
Profiling user guide:
https://www.codeigniter.com/user_guide/general/profiling.html
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