Question

This is my table:

URL           | Art | Design 
example1.com     1             
example1.com     1             
example1.com     1             
example1.com            1         
example2.com            1
example2.com            1

I want to merge columns with same URL and sum the values of Art and Design in the process, to get something like:

URL           | Art | Design
example1.com     3      1
example2.com            2

How is this done?

Answer 1

Use GROUP BY and SUM:

SELECT URL, SUM(Art) as Art, SUM(Design) AS Design
FROM yourtable
GROUP BY URL