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Possible to do a MySQL foreign key to one of two possible tables?
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What you're describing is called Polymorphic Associations. That is, the "foreign key" column contains an id value that must exist in one of a set of target tables. Typically the target tables are related in some way, such as being instances of some c...
Why is char[] preferred over String for passwords?
... believe this is implementation-specific - the garbage collector may clear all memory as it goes, to avoid this sort of thing. Even if it does, there's still the time during which the char[] contains the actual characters as an attack window.
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What is a stack trace, and how can I use it to debug my application errors?
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In simple terms, a stack trace is a list of the method calls that the application was in the middle of when an Exception was thrown.
Simple Example
With the example given in the question, we can determine exactly where the exception was thrown in the application. Let's have a lo...
How to stop a JavaScript for loop?
...try.size === remData.size;
});
Array#findIndex stops the first time the callback returns a truthy value, returning the index for that call to the callback; it returns -1 if the callback never returns a truthy value. Array#find also stops when it finds what you're looking for, but it returns the en...
find: missing argument to -exec
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A -exec command must be terminated with a ; (so you usually need to type \; or ';' to avoid interpretion by the shell) or a +. The difference is that with ;, the command is called once per file, with +, it is called just as few times as possible (usually once, but there is a maxi...
Twitter Bootstrap 3 Sticky Footer
...olor: #f5f5f5;
}
and the essential HTML:
<body>
<!-- Wrap all page content here -->
<div id="wrap">
<!-- Begin page content -->
<div class="container">
</div>
</div>
<div id="footer">
<div class="contai...
scheduleAtFixedRate vs scheduleWithFixedDelay
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Try adding a Thread.sleep(1000); call within your run() method... Basically it's the difference between scheduling something based on when the previous execution ends and when it (logically) starts.
For example, suppose I schedule an alarm to go off with a f...
ACE vs Boost vs POCO [closed]
... situation. The good things about POCO IMO:
Better thread library, especially a Active Method implementation. I also like the fact that you can set the thread priority.
More comprehensive network library than boost::asio. However boost::asio is also a very good library.
Includes functionality that...
Transaction isolation levels relation with locks on table
...B just executes a SELECT statement to read data. C reads and updates data. All these process work on the same table T.
READ UNCOMMITTED - no lock on the table. You can read data in the table while writing on it. This means A writes data (uncommitted) and B can read this uncommitted data and use it...
How can I copy the content of a branch to a new local branch?
...e work completely. I was thinking of something like create a new branch locally and copy the old branch there, then I can revert the changes and continue working on the old branch. Is there a better way maybe? Or how do I do this?
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