Data Sum Return

Hello everyone, everything good ?
I need to create a repetition loop to go through my database and return the sum of all the data in a given column, but only the data that has a criterion as a reference.
I’m not able to understand the logic and reproduce it in the blocks, can someone help me, please?

You need to provide an example of what you mean. Also, if you’ve tried to set up blocks for this, include a screenshot and explain what has and has not worked.