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How to check for Is not Null And Is not Empty string in SQL server?
...with NULL or an empty string or a string consisting entirely of spaces are all excluded by this query.
SQL Fiddle
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Block Declaration Syntax List
...at this is distinct from "Blocks as Parameters"; in this instance, you're calling a method that wants a block argument with an anonymous block. If you have already declared a block variable, it is sufficient to pass the variable name as the argument.
[someObject doSomethingWithBlock: ^return_type (...
Why do C++ libraries and frameworks never use smart pointers?
... their implementations.
But because of the lack of standard ABI, you generally cannot pass these objects safely across module boundaries. A GCC shared_ptr is probably different from an MSVC shared_ptr, which too can differ from an Intel shared_ptr. Even with the same compiler, these classes are not...
How can I build a small operating system on an old desktop computer? [closed]
...in, as I know writing an operating system is unbearably complicated (especially by oneself).
20 Answers
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How to get “wc -l” to print just the number of lines without file name?
...is the most concise, and awk and perl seem a bit overkill, but they should all be relatively fast and portable enough.
Also note that some of these can be adapted to trim surrounding whitespace from general strings, as well (along with echo `echo $FOO`, another neat trick).
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What is fastest children() or find() in jQuery?
... depends on whether you only want to consider the immediate descendants or all nodes below this one in the DOM, i.e., choose the appropriate method based on the results you desire, not the speed of the method. If performance is truly an issue, then experiment to find the best solution and use that (...
Advantage of switch over if-else statement
... the average case) or simply build a jump-table (works without compares at all).
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Default visibility of class methods in PHP
...sibility.
<?php
class Example {
public $name;
public function __construct() {
$this -> age = 9; // age is now public
$this -> privateFunction();
}
private function privateFunction() {
$this -> country = "USA"; // this is also public
}
}
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How to convert a table to a data frame
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I figured it out already:
as.data.frame.matrix(mytable)
does what I need -- apparently, the table needs to somehow be converted to a matrix in order to be appropriately translated into a data frame. I found more details on this as.data.frame.matrix() function for con...
Does MySQL ignore null values on unique constraints?
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Yes, MySQL allows multiple NULLs in a column with a unique constraint.
CREATE TABLE table1 (x INT NULL UNIQUE);
INSERT table1 VALUES (1);
INSERT table1 VALUES (1); -- Duplicate entry '1' for key 'x'
INSERT table1 VALUES (NULL);
INSER...