Volume weighted trend (or averaging functions)

I have data coming at irregular intervals, but when they come, they have quite high density.
The time span needs to be high (weeks or months) to show the holistic picture.
What i need is to show a volume weighted graph, which shows the average of the datapoints.
I prefer to get a line instead of nothing for 5 days and then something that looks more like an array of points, making zooming in and out nessecary to understand which level it actually mostly was at.

Any suggestions? Maybe some sort of sql query line can be used?