Sqlite database has some Nulls how to create a line graph?

Hi,
I want to make a graph from my data, the Temperatures etc, come in at random times and updates it's own column and Nulls are put in every other column.

The Nulls would mess up the graph, is there a way to change Nulls to previous non null reading or as the chart is shown on Dashboard ?.

An example of what I am looking to do.

IP_24_Temperature  IP_24_Humidity
16.5			            Null
Null			            Null
Null			            Null
16.8	                            58
Null	                            Null
Null	                            Null
Null	                            Null
Null	                            60
Null	                           Null
16.5	                            61

What I require is ...

IP_24_Temperature  IP_24_Humidity
16.5			                 0
16.5			                 0
16.5			                 0
16.8	                               58
16.8	                               58
16.8	                               58
16.8	                               58
16.8	                               60
16.8	                               60
16.5	                               61

...... etc

Thanks

Why do you have your database setup that way, wouldn't it be better (and easier) to have column labeled 'device' or 'uint' and put the device name there with it's readings. So you would end up with
ID, Device, Unix_Time, Day, Date, Time, Humidity, Temperature
Then you could query by device and adding another device would be easy as using the new name. Also, why store the Day, Date and Time when you have the Unix_time? So your table could be
ID, Device, Unix_Time, Humidity, Temperature
and you could convert the Unix_time to what ever date format you want (note: as of NR v1.1.0 the change node supports the moment.js library. Here is a thread explaining how to use it Formatting times & dates with moment.js examples

Hi,

I think I have understood what you mean ...

Here is a mock up of your idea ?

Thanks

ScreenHunter_20155 Oct. 10 17.48

That correct, with it that way you can access the readings by device and shouldn’t have to worry about nulls