I want to know what is better.
- save all data (for example skype,icq,facebook,stackoverflow,etc,etc,etc) profiles in one column
- save data in separated columns (separated column for skype, icq, facebook, stackoverflow, etc,etc)
What is better and easy for mysql server?
Saving them all in one column would violate first normal form and make querying and aggregating the data very difficult.
Use one column to store each piece of information.
If you are storing profile data for each service, you might even be better of with a separate table per service, with a foreign key to the user id.