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How to use GROUP_CONCAT in a CONCAT in MySQL
.... I always use this separator, because it's impossible to find it inside a string, therefor it's unique.
There is no problem having two A's, you identify only the value. Or you can have one more colum, with the letter, which is even better.
Like this :
SELECT id,GROUP_CONCAT(DISTINCT(name)), GROUP_...
What does “Could not find or load main class” mean?
...with signature, return type and modifiers given by public static void main(String[]). (Note, the method argument's name is NOT part of the signature.)
Call that method passing it the command line arguments ("fred", "joe", "bert") as a String[].
Reasons why Java cannot find the class
When you get...
What ReSharper 4+ live templates for C# do you use? [closed]
...
Check if a string is null or empty.
If you're using .Net 4 you may prefer to use string.IsNullOrWhiteSpace().
Shortcut: sne
Available in: C# 2.0+ where expression is allowed.
string.IsNullOrEmpty($VAR$)
Macro properties:
VAR - suggest...
Is the list of Python reserved words and builtins available in a library?
...
To verify that a string is a keyword you can use keyword.iskeyword; to get the list of reserved keywords you can use keyword.kwlist:
>>> import keyword
>>> keyword.iskeyword('break')
True
>>> keyword.kwlist
['False...
Combining two expressions (Expression)
...t;(body, newParameter);
}
[TestMethod]
public void ExpressionText()
{
string text = "test";
Expression<Func<Coco, bool>> expr1 = p => p.Item1.Contains(text);
Expression<Func<Coco, bool>> expr2 = q => q.Item2.Contains(text);
Expression<Func<Coco, ...
Copy array by value
...ay and returns a reference to a new array.
Also note that:
For references, strings and numbers (and not the actual object), slice() copies object references into the new array. Both the original and new array refer to the same object. If a referenced object changes, the changes are visible to both t...
How do I read / convert an InputStream into a String in Java?
....io.InputStream object, how should you process that object and produce a String ?
59 Answers
...
How do I run a spring boot executable jar in a Production environment?
...otApplication
public class MyAppInitializer {
public static void main(String[] args) {
SpringApplication.run(MyAppInitializer .class, args);
}
}
My Initializer for production environment extends the SpringBootServletInitializer and looks like this:
@SpringBootApplication
public ...
How to “EXPIRE” the “HSET” child key in redis?
...d zset Redis objects under the hood. Usage example:
RMapCache<Integer, String> map = redisson.getMapCache('map');
map.put(1, 30, TimeUnit.DAYS); // this entry expires in 30 days
This approach is quite useful.
share
...
AJAX POST and Plus Sign ( + ) — How to Encode?
...at have already been decoded.
Example:
In your JS:
// url encode your string
var string = encodeURIComponent('+'); // "%2B"
// send it to your server
window.location = 'http://example.com/?string='+string; // http://example.com/?string=%2B
On your server:
echo $_GET['string']; // "+"
It is...