Alter query to set foreign key

ALTER TABLE tablename_to_add_foreignkey ADD CONSTRAINT constraint_name FOREIGN KEY (fieldname) REFERENCES sports (reference_fieldname)

Skype not seen in notification area

A couple of days ago my Skype apps won't show in the panel like they usually would. They are launching i know that much because when i try to run Skype manually it tells me there's already another instance of Skype already running. I haven't made any system changes at all except for any updates that have come available automatically through the package manager.

"Notification area is missing.

Right click on Top/Bottom panel > Add to Panel > Notification area > Add

Removing the index.php file in Codeigniter

By default, the index.php file will be included in your URLs:
example.com/index.php/news/article/my_article

You can easily remove this file by using a .htaccess file with some simple rules. Here is an example of such a file, using the "negative" method in which everything is redirected except the specified items:
RewriteEngine on
RewriteCond $1 !^(index\.php|images|robots\.txt)
RewriteRule ^(.*)$ /index.php/$1 [L]

In the above example, any HTTP request other than those for index.php, images, and robots.txt is treated as a request for your index.php file.