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PostgreSQL: Difference between text and varchar (character varying)
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There is no difference, under the hood it's all varlena (variable length array).
Check this article from Depesz: http://www.depesz.com/index.php/2010/03/02/charx-vs-varcharx-vs-varchar-vs-text/
A couple of highlights:
To sum it all up:
char(n) – takes t...
Getting and removing the first character of a string
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x <- 'hello stackoverflow'
substring(x, 2, nchar(x))
Idea is select all characters starting from 2 to number of characters in x. This is important when you have unequal number of characters in word or phrase.
Selecting the first letter is trivial as previous answers:
substring(x,1,1)
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Is it correct to use JavaScript Array.sort() method for shuffling?
... ends up as a more complex (in terms of execution time) shuffle than you really need.
I prefer the shuffle algorithm which effectively partitions the collection into "shuffled" (at the start of the collection, initially empty) and "unshuffled" (the rest of the collection). At each step of the algori...
What is the difference between HTML tags and ?
...k element
span is an inline element.
This means that to use them semantically, divs should be used to wrap sections of a document, while spans should be used to wrap small portions of text, images, etc.
For example:
<div>This a large main division, with <span>a small bit</span>...
AJAX Mailchimp signup form integration
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You don't need an API key, all you have to do is plop the standard mailchimp generated form into your code ( customize the look as needed ) and in the forms "action" attribute change post?u= to post-json?u= and then at the end of the forms action appen...
How to store a command in a variable in a shell script?
... that variable can be set by someone with less privileges. (Iterating over all subdirectories in /tmp, for instance? You'd better trust every single user on the system to not make one called $'/tmp/evil-$(rm -rf $HOME)\'$(rm -rf $HOME)\'/').
– Charles Duffy
Jun...
How to convert a boolean array to an int array
...veryone for you help!....although the answer was right in my question, i really liked getting the variety of answers and seeing all the different ways to do it. Really opened my mind regarding python.
– Kwolf
Jul 6 '13 at 20:49
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pandas: filter rows of DataFrame with operator chaining
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That is a really nice solution - I wasn't even aware that you could jury-rig methods like that in python. A function like this would be really nice to have in Pandas itself.
– naught101
Mar 3 '17 at...
How to round a number to n decimal places in Java
...ues into account. Floating point values have a binary representation internally. That means that a value like 2.7735 does not actually have that exact value internally. It can be slightly larger or slightly smaller. If the internal value is slightly smaller, then it will not round up to 2.7740. To r...
PHP: If internet explorer 6, 7, 8 , or 9
...mp;& $B['v'] <= 8) {
// Browsers IE 8 and below
} else {
// All other browsers
}
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