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String.IsNullOrWhiteSpace in LINQ Expression
...INQ provider to deliver an optimized query. During this transformation not all C# statements are supported, as it either is not possible to translate them to a back-end specific query (e.g. SQL) or because the implementer did not foresee the need for the statement.
In contrast IEnumerable<T>...
What's the difference between INNER JOIN, LEFT JOIN, RIGHT JOIN and FULL JOIN? [duplicate]
...- the join can be one->one, one->many, or many->many. So it's actually impossible to represent with a Venn diagram: all this diagram does is show you "what portion of the table will be involved in the join." In which case select a.* from a cross join b should have the same diagram as full o...
Why Func instead of Predicate?
...
Well, actually you have to place that in the context of the guideline, which is about writing a LINQ provider. So yeah, for LINQ operators, the guideline is to use Func<> and Expression<> as parameters for the extension met...
What makes a SQL statement sargable?
...L optimizer can't use an index on myDate, even if one exists. It will literally have to evaluate this function for every row of the table. Much better to use:
WHERE myDate >= '01-01-2008' AND myDate < '01-01-2009'
Some other examples:
Bad: Select ... WHERE isNull(FullName,'Ed Jones') = 'Ed...
Difference between @import and link in CSS
...nsive blog post comparing the impact of both <link> and @import (and all sorts of combinations of them) called "don’t use @import". That title pretty much speaks for itself.
Yahoo! also mentions it as one of their performance best practices (co-authored by Steve Souders): Choose <link>...
Log to the base 2 in python
...hat
but also know that
math.log takes an optional second argument which allows you to specify the base:
In [22]: import math
In [23]: math.log?
Type: builtin_function_or_method
Base Class: <type 'builtin_function_or_method'>
String Form: <built-in function log>
Namespace: ...
Git: which is the default configured remote for branch?
...ory for pushing and pulling using git-branch’s track option. You’d normally do this by specifying the --track option when creating your local master branch, but as it already exists we’ll just update the config manually like so:
Edit your .git/config
[branch "master"]
remote = origin
mer...
jQuery Determine if a matched class has a given id
...he selector by combining multiple selectors. For instance, we could target all elements with a given id, that also have a particular class:
$("#foo.bar"); // Matches <div id="foo" class="bar">
This should look similar to something you'd write in CSS. Note that it won't apply to all #foo ele...
Segmentation fault on large array sizes
...The array is too big to fit in your program's stack address space.
If you allocate the array on the heap you should be fine, assuming your machine has enough memory.
int* array = new int[1000000];
But remember that this will require you to delete[] the array. A better solution would be to use st...
How can I provide multiple conditions for data trigger in WPF?
...D are false, and set the default to true.
– WeSam Abdallah
Oct 28 '14 at 15:47
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