Designer - reporting - Timeseries - Gaps when data has null


I tried to create a timeseries chart in the report designer and found gaps in the time series. I struggled for a while with the gap threashold and trying to find what caused this.

As my database has null values for incomplete datasets I found that the charts then had gaps when trying to create a timeseries. This was resolved by setting the query to exclude null values when returning rows and used the clause: where columname IS NOT NULL

Attached is a screenshot, I thought I would just document this to help anyone else who came across this.

Hello all,

So while my solution worked for one set of data where I can skip null, I have a problem with another set where excluding null interferes with the dataset. If anyone has any ideas on how to get the chart to draw lines between null values it would be appreciated if you can share them.

If I recall correctly, the underlying JFreeChart objects expects nulls as indicators to deliberately break continuous lines. If so, you won’t find a solution short of completely re-implementing JFreeChart’s renderers. You might just have to create a non-null value from the adjacent rows to replace the null.

Hello Phil,
Thank you for your response, I do see what you mean about JFreeChart’s renderers.
I’ll update all on how I get along from here.