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COUNT(*) vs. COUNT(1) vs. COUNT(pk): which is better? [duplicate]
...T(field) or COUNT(*), and stick with it consistently, and if your database allows COUNT(tableHere) or COUNT(tableHere.*), use that.
In short, don't use COUNT(1) for anything. It's a one-trick pony, which rarely does what you want, and in those rare cases is equivalent to count(*)
Use count(*) fo...
How to check whether mod_rewrite is enable on server?
...nfiguration file, make sure the virtual host in question has the directive AllowOverride All somewhere like this:
<VirtualHost *:80>
...
<Directory "directory/of/your/.htaccess">
AllowOverride All
</Directory>
</VirtualHost>
Basically, this states to ...
How to integrate CSS pre-processing within Eclipse? [closed]
...t it's waaaaay better than looking at plain text and you don't need to install a separate editor.
You need to associate the .scss file type with the native Eclipse CSS Editor in Eclipse[Part 1]. After you do that, you need to add the .scss file type to the native CSS Editor as well so the CSS Edit...
What is output buffering?
...se it's not being sent to the browser in pieces as PHP processes the HTML.
All the fancy stuff we can do with PHP strings, we can now do with our whole HTML page as one variable.
If you've ever encountered the message "Warning: Cannot modify header information - headers already sent by (output)" whi...
The performance impact of using instanceof in Java
...y heavy use of the instanceof operator. While I know that OO design generally tries to avoid using instanceof , that is a different story and this question is purely related to performance. I was wondering if there is any performance impact? Is is just as fast as == ?
...
Task vs Thread differences [duplicate]
I'm new to parallel programming. There are two classes available in .NET: Task and Thread .
4 Answers
...
Check if table exists and if it doesn't exist, create it in SQL Server 2008
...read, and you don't have to worry about sys.objects vs. sysobjects vs. sys.all_objects
vs. sys.tables. Basic form:
IF object_id('MyTable') is not null
PRINT 'Present!'
ELSE
PRINT 'Not accounted for'
Of course this will show as "Present" if there is any object present with that name. If yo...
How do you remove Subversion control for a folder?
... getting back your folder icon in normal restart the svn server and that's all
– 3ehrang
Feb 27 '12 at 8:58
The server...
What is the difference between a field and a property?
...sed via get and set properties. Properties provide a level of abstraction allowing you to change the fields while not affecting the external way they are accessed by the things that use your class.
public class MyClass
{
// this is a field. It is private to your class and stores the actual da...
Clone() vs Copy constructor- which is recommended in java [duplicate]
...rclass since the
Beta-release days of the Java
compiler*; and it, like all ancient
magic, requires the appropriate
incantation to prevent the spell from
unexpectedly backfiring
Prefer a method that copies the object
Foo copyFoo (Foo foo){
Foo f = new Foo();
//for all properties in F...