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Swapping column values in MySQL
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I just had to deal with the same and I'll summarize my findings.
The UPDATE table SET X=Y, Y=X approach obviously doesn't work, as it'll just set both values to Y.
Here's a method that uses a temporary variable. Thanks to Antony from the comments of http://beerpla.net/200...
How to check if a string contains a substring in Bash
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michael-slx
19122 silver badges77 bronze badges
answered Oct 23 '08 at 12:55
Adam BellaireAdam Bellaire
95.6k1919 go...
How to tell if a string is not defined in a Bash shell script
...To distinguish whether VAR is set but empty or not set, you can use:
if [ -z "${VAR+xxx}" ]; then echo VAR is not set at all; fi
if [ -z "$VAR" ] && [ "${VAR+xxx}" = "xxx" ]; then echo VAR is set but empty; fi
You probably can combine the two tests on the second line into one with:
if [ -z ...
How to create a new object instance from a Type
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Jay
14433 silver badges1616 bronze badges
answered Aug 3 '08 at 16:35
Karl SeguinKarl Seguin
19.9k55 gold badg...
CSS z-index paradox flower
I would like to create a paradoxical effect via the z-index CSS property.
6 Answers
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How do I translate an ISO 8601 datetime string into a Python datetime object? [duplicate]
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I prefer using the dateutil library for timezone handling and generally solid date parsing. If you were to get an ISO 8601 string like: 2010-05-08T23:41:54.000Z you'd have a fun time parsing that with strptime, especially if you didn't know up front whether or not the ...
What does -z mean in Bash? [duplicate]
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-z string True if the string is null (an empty string)
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Evenly distributing n points on a sphere
... you, hopefully you can use that now.
(in other words, k is an array of size N that is defined before the code fragment starts, and which contains a list of the points).
Alternatively, building on the other answer here (and using Python):
> cat ll.py
from math import asin
nx = 4; ny = 5
for x ...
Scala constructor overload?
...ructor is the sole point of entry to the class.
class Foo(x: Int, y: Int, z: String) {
// default y parameter to 0
def this(x: Int, z: String) = this(x, 0, z)
// default x & y parameters to 0
// calls previous auxiliary constructor which calls the primary constructor
def this...
Is it possible to apply CSS to half of a character?
...w on GitHub as a Plugin!
Feel free to fork and improve.
Demo | Download Zip | Half-Style.com (Redirects to GitHub)
Pure CSS for a Single Character
JavaScript used for automation across text or multiple characters
Preserves Text Accessibility for screen readers for the blind or visually
impair...