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How do I (or can I) SELECT DISTINCT on multiple columns?
...would qualify as "distinct" (though looking identical to the human eye):
(123, NULL)
(123, NULL)
Also passes in a unique index and almost anywhere else, since NULL values do not compare equal according to the SQL standard. See:
Create unique constraint with null columns
OTOH, GROUP BY, DISTIN...
Why doesn't C# support the return of references?
...rn ref x;
else
return ref y;
}
and then call it with
int a = 123;
int b = 456;
ref int c = ref Max(ref a, ref b);
c += 100;
Console.WriteLine(b); // 556!
I know empirically that it is possible to build a version of C# that supports these features because I have done so. Advanced pr...
How do I find where JDK is installed on my windows machine?
...
If you are using Linux/Unix/Mac OS X:
Try this:
$ which java
Should output the exact location.
After that, you can set JAVA_HOME environment variable yourself.
In my computer (Mac OS X - Snow Leopard):
$ which java
/usr/bin/java
$ ls -l /usr/bin/java...
How to tell if node.js is installed or not
...
Your OS is either 32-bit or 64-bit. When you install nodejs it picks the matching version.
– arikin
Apr 2 '15 at 7:50
...
How do I use the nohup command without getting nohup.out?
...sn't create nohup.out
On Linux, running a job with nohup automatically closes its input as well. On other systems, notably BSD and macOS, that is not the case, so when running in the background, you might want to close input manually. While closing input has no effect on the creation or not of no...
How to use Git for Unity3D source control?
...up to date version checkout Github maintained Unity.gitignore file without OS specifics.
# =============== #
# Unity generated #
# =============== #
Temp/
Library/
# ===================================== #
# Visual Studio / MonoDevelop generated #
# ===================================== #
Exported...
Best way to define private methods for a class in Objective-C
...e method in Objective-C. However, starting in Objective-C 2.0 (meaning Mac OS X Leopard, iPhone OS 2.0, and later) you can create a category with an empty name (i.e. @interface MyClass ()) called Class Extension. What's unique about a class extension is that the method implementations must go in the...
How to add pandas data to an existing csv file?
I want to know if it is possible to use the pandas to_csv() function to add a dataframe to an existing csv file. The csv file has the same structure as the loaded data.
...
How set background drawable programmatically in Android
...nother way to achieve it is to use the following:
final int sdk = android.os.Build.VERSION.SDK_INT;
if(sdk < android.os.Build.VERSION_CODES.JELLY_BEAN) {
layout.setBackgroundDrawable(ContextCompat.getDrawable(context, R.drawable.ready) );
} else {
layout.setBackground(ContextCompat.getDr...
Call a function from another file?
...to do with Python 3, or is a general problem?
– DarkRose
Jun 29 '15 at 7:02
7
@GamesBrainiac, wha...