Thanks for your solution. I see you have solved in in the script. I didn't think of that.Thanks.
One more question for now: when I have 2 lines on the same date, that the SUM(balance) doesn't work.
Let's say I add a line:
11111111, 2014-01-01, 200
Then my balance of 2014-01-01 is 1000+200+1000+200. How can I solve that? I also have an ID on my table. I probably can use that one. But per unique date I want a value in my graph.
Perhaps this document helps with getting the balance amounts right: Calculating rolling n-period totals, averages or other aggregations. The AsOf Table Examples.qvw example app contains a RollingToDate option that looks like what you could use.