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How do I check if a column is empty or null in MySQL?
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This will select all rows where some_col is NULL or '' (empty string)
SELECT * FROM table WHERE some_col IS NULL OR some_col = '';
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Access Enum value using EL with JSTL
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A simple comparison against string works:
<c:when test="${someModel.status == 'OLD'}">
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Map to String in Java
...n(map) in Java, I get a nice output in stdout. How can I obtain this same string representation of a Map in a variable without meddling with standard output? Something like String mapAsString = Collections.toString(map) ?
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What's the difference between istringstream, ostringstream and stringstream? / Why not use stringstr
When would I use std::istringstream , std::ostringstream and std::stringstream and why shouldn't I just use std::stringstream in every scenario (are there any runtime performance issues?).
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Why do == comparisons with Integer.valueOf(String) give different results for 127 and 128?
...r.parseInt("123");
This returns an int primitive value after parsing the String.
Integer.valueOf("123");
This is more complex than the others. It starts off by parsing the String. Then, if the value is between -128 and 127, it returns the corresponding object from the static cache. If the va...
Why is Java's SimpleDateFormat not thread-safe? [duplicate]
... }
};
}
public SimpleDateFormatThreadSafe(final String pattern) {
super(pattern);
localSimpleDateFormat = new ThreadLocal<SimpleDateFormat>() {
protected SimpleDateFormat initialValue() {
return new SimpleDateFormat(pattern...
Is there a Java equivalent or methodology for the typedef keyword in C++?
...ss you would like to typedef, e.g.:
public class MyMap extends HashMap<String, String> {}
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What is the difference between '@' and '=' in directive scope in AngularJS?
...title1 or title="title1", the value of DOM attribute "title" is simply the string title1. If you use title="{{title}}", the value of the DOM attribute "title" is the interpolated value of {{title}}, hence the string will be whatever parent scope property "title" is currently set to. Since attribut...
What's the difference between dynamic (C# 4) and var?
...ng are 100% identical:
var s = "abc";
Console.WriteLine(s.Length);
and
string s = "abc";
Console.WriteLine(s.Length);
All that happened was that the compiler figured out that s must be a string (from the initializer). In both cases, it knows (in the IL) that s.Length means the (instance) strin...
Converting Symbols, Accent Letters to English Alphabet
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Reposting my post from How do I remove diacritics (accents) from a string in .NET?
This method works fine in java (purely for the purpose of removing diacritical marks aka accents).
It basically converts all accented characters into their deAccented counterparts followed by their combining...