I have a table with ticket sales.
In one column the amount of tickets the customer order is listed.
So, if one order 2 tickets that column will show 2, if someone order 8 tickets, that column is showing 8, a.s.o.

Now I would like to just pick out the sum of all tickets sold so far.
Don't know how to do that. What should I use? I guess there is something very simple to do this.

The table is called showtickets
The column is called tickets