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SQL is null and = null [duplicate]
...alue (including another null) using a comparison operator (eg =, !=, <, etc) will result in a null, which is considered as false for the purposes of a where clause (strictly speaking, it's "not true", rather than "false", but the effect is the same).
The reasoning is that a null means "unknown",...
Concatenating multiple text files into a single file in Bash
...t, you should either name the files appropriately (01file.txt, 02file.txt, etc...) or specify each file in the order you want it concatenated.
$ cat file1 file2 file3 file4 file5 file6 > out.txt
share
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How to use GROUP_CONCAT in a CONCAT in MySQL
...what you need.
Update
Splitting in two steps. First we get a table having all values(comma separated) against a unique[Name,id]. Then from obtained table we get all names and values as a single value against each unique id
See this explained here SQL Fiddle Demo (scroll down as it has two result se...
REST API 404: Bad URI, or Missing Resource?
...ifference, but that doesn't imply that an empty string is an error. To stretch the analogy: You could have a method String getName() that has an implementation like this: return this.name == null ? "" : this.name. That's not incorrect unless you want the client to know that this.name is null.
...
Overcoming “Display forbidden by X-Frame-Options”
...n pages), simply sending another X-Frame-Options header with any string at all disables the SAMEORIGIN or DENY commands.
eg. for PHP, putting
<?php
header('X-Frame-Options: GOFORIT');
?>
at the top of your page will make browsers combine the two, which results in a header of
X-Frame...
Unique ways to use the Null Coalescing operator [closed]
...
Well, first of all, it's much easier to chain than the standard ternary:
string anybody = parm1 ?? localDefault ?? globalDefault;
vs.
string anyboby = (parm1 != null) ? parm1
: ((localDefault != null) ? localDefault
...
Scala equivalent of Java java.lang.Class Object
...: java.lang.Class[C] = class C
scala> c.getClass
res1: java.lang.Class[_] = class C
That is why the following will not work:
val xClass: Class[X] = new X().getClass //it returns Class[_], nor Class[X]
val integerClass: Class[Integer] = new Integer(5).getClass //similar error
There is a ticket...
How to go to a specific element on page? [duplicate]
...
+1 for the native scrollIntoView which i didnt know at all. for a moment i thought it was jquery. :)
– naveen
Jan 26 '11 at 6:15
...
Factory Pattern. When to use factory methods?
...one, you need to know a lot of stuff - benefits, eligibility verification, etc. But the person hiring doesn't need to know any of this - the hiring agency handles all of that.
In the same way, using a Factory allows the consumer to create new objects without having to know the details of how they...
.NET Process.Start default directory?
...\system32.
You can determine the value of %SYSTEMROOT% by using:
string _systemRoot = Environment.GetEnvironmentVariable("SYSTEMROOT");
Here is some sample code that opens Notepad.exe with a working directory of %ProgramFiles%:
...
using System.Diagnostics;
...
ProcessStartInfo _processStar...