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'Must Override a Superclass Method' Errors after importing a project into Eclipse
... preferences and set the Java compiler level to 1.6 and also make sure you select JRE 1.6 to execute your program from Eclipse.
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LINQ order by null column where order is ascending and nulls should be last
... descending
orderby p.LowestPrice descending
select p;
will be translated by the compiler to
var products = _context.Products
.Where(p => p.ProductTypeId == 1)
.OrderByDescending(p => p.LowestPrice.HasValue)
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Which kind of pointer do I use when?
...covariant return and non-owning. A rewrite might be good if you meant the union rather than intersection. I'd also say that iteration is worth special mention also.
– Ben Voigt
Jan 2 '12 at 23:11
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How can I handle time zones in my webapp?
...ssume that timezone.
Should the device switch timezones, add a dropdown to select which timezone the event is in, defaulting to the device's own timezone.
Add an option to show/hide this timezone dropdown manually.
Always store timestamps in UTC.
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What are the Dangers of Method Swizzling in Objective-C?
... class_getInstanceMethod(class, original);
if (method) {
const char *type = method_getTypeEncoding(method);
imp = class_replaceMethod(class, original, replacement, type);
if (!imp) {
imp = method_getImplementation(method);
}
}
if (imp &&...
JavaScript open in a new window, not tab
I have a select box that calls window.open(url) when an item is selected. Firefox will open the page in a new tab by default. However, I would like the page to open in a new window, not a new tab.
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How to clear MemoryCache?
...od
The workaround is:
List<string> cacheKeys = MemoryCache.Default.Select(kvp => kvp.Key).ToList();
foreach (string cacheKey in cacheKeys)
{
MemoryCache.Default.Remove(cacheKey);
}
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What is a NullReferenceException, and how do I fix it?
... to find out where the reference is or isn't set, right-click its name and select "Find All References". You can then place a breakpoint at every found location and run your program with the debugger attached. Every time the debugger breaks on such a breakpoint, you need to determine whether you exp...
Computed / calculated / virtual / derived columns in PostgreSQL
...y as column?
The expression (looking like a column) is not included in a SELECT * FROM tbl, though. You always have to list it explicitly.
Can also be supported with a matching expression index - provided the function is IMMUTABLE. Like:
CREATE FUNCTION col(tbl) ... AS ... -- your computed expr...
What's the recommended approach to resetting migration history using Django South?
...ps, so make sure you either run the other two lines for all apps or delete selectively).
The convert_to_south call at the end makes a new migration and fake-applies it (since your database already has the corresponding tables). There's no need to drop all the app tables during the process.
He...