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What are '$$' used for in PL/pgSQL
...c to function definitions. It can be used to replace single quotes practically anywhere in SQL scripts.
The body of a function happens to be a string literal which has to be enclosed in single quotes. Dollar-quoting is a PostgreSQL-specific substitute for single quotes to avoid quoting issues insi...
What are the differences between 'call-template' and 'apply-templates' in XSL?
...
<xsl:call-template> is a close equivalent to calling a function in a traditional programming language.
You can define functions in XSLT, like this simple one that outputs a string.
<xsl:template name="dosomething">
&l...
How to compare versions in Ruby?
... The Gem::Version... syntax made me thought I would need to install a gem. But it was not required.
– Guillaume
Oct 17 '12 at 17:08
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How do I get the file extension of a file in Java?
...
Do you really need a "parser" for this?
String extension = "";
int i = fileName.lastIndexOf('.');
if (i > 0) {
extension = fileName.substring(i+1);
}
Assuming that you're dealing with simple Windows-like file names, not som...
How do I do multiple CASE WHEN conditions using SQL Server 2008?
...
I had a similar but it was dealing with dates.
Query to show all items for the last month, works great without conditions until Jan.
In order for it work correctly, needed to add a year and month variable
declare @yr int
declare @mth int
set @yr=(select case when month(getdate())=1 t...
What unique features does Firebug have that are not built-in to Firefox?
...There are more things missing, which are tracked in a bug report filed for all the gaps between Firebug and the Firefox DevTools.
Firebug integration
Firebug is now built on top of the native developer tools.
Since Firefox 48 there's also a Firebug theme that looks like the Firebug extension, lett...
What is more efficient: Dictionary TryGetValue or ContainsKey+Item?
...ll be faster.
ContainsKey uses the same check as TryGetValue, which internally refers to the actual entry location. The Item property actually has nearly identical code functionality as TryGetValue, except that it will throw an exception instead of returning false.
Using ContainsKey followed by t...
Reloading submodules in IPython
...atic reloading magic:
%load_ext autoreload
%autoreload 2
It will reload all changed modules every time before executing a new line. The way this works is slightly different than dreload. Some caveats apply, type %autoreload? to see what can go wrong.
If you want to always enable this settings,...
How to distinguish mouse “click” and “drag”
...dited Jun 26 '19 at 12:45
Rivenfall
80466 silver badges1414 bronze badges
answered May 18 '11 at 9:03
wong2won...
Convert data.frame columns from factors to characters
I have a data frame. Let's call him bob :
18 Answers
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