Looking for intersection of data points

InfluxDB 1 InfluxQL
1

I have a simple time series where I want to return the unix timestamp of each intersection of data points. I would like a query that returns the timestamps (0 or more) where the value of XV is the same (or within a threshold of ~2) for each SensorLocation at the same timestamp. Basically, if all values at all locations are equal or close to each other, return the timestamp… and XV values I guess. Also for a specific time range like the past 8 hours.

name: Enviro
time SensorLocation XV

1721674643000000000 SouthEast 103
1721674695000000000 SouthWest 56
1721674700000000000 NorthWest 77
1721674707000000000 SouthEast 96
1721674772000000000 SouthWest 54
1721674777000000000 NorthEast 69
1721674783000000000 NorthWest 71
1721674797000000000 SouthEast 81
1721674847000000000 SouthWest 53
1721674855000000000 NorthEast 64
1721674861000000000 NorthWest 67
1721674874000000000 SouthEast 79
1721674912000000000 SouthWest 51
1721674919000000000 NorthEast 61
1721674919000000000 NorthWest 61
1721674919000000000 SouthEast 61
1721674919000000000 SouthWest 61
1721674924000000000 NorthWest 67
1721674941000000000 SouthEast 77
1721674975000000000 SouthWest 53
1721674982000000000 NorthEast 61
1721674988000000000 NorthWest 67
1721675004000000000 SouthEast 77
1721675036000000000 SouthWest 53
1721675043000000000 NorthEast 61
1721675049000000000 NorthWest 67
1721675066000000000 SouthEast 76
1721675066000000000 SouthWest 76
1721675066000000000 NorthEast 76
1721675066000000000 NorthWest 76
1721675098000000000 SouthWest 53
1721675107000000000 NorthEast 61
1721675111000000000 NorthWest 67
1721675127000000000 SouthEast 76
1721675160000000000 SouthWest 50
1721675170000000000 NorthEast 61
1721675173000000000 NorthWest 65
1721675189000000000 SouthEast 76
1721675227000000000 SouthWest 50

2

Hi @mdetweiler, To find the timestamps where all sensor locations have similar XV values you can write an InfluxQL query that selects timestamps and XV values from your “Enviro” measurement. Limit the data to the last 8 hours, group by timestamp and SensorLocation, and use a HAVING clause to ensure all sensors are present and their XV values are within 2 units of each other. You might want to look at functions like SPREAD() or MAX() and MIN() to compare values.

Hope that helps.

3

Thank you for the advice. I’ll see if I can make it work.

1 Like
4

Looks like InfluxQL doesn’t support HAVING?

5

You’re right, I confused it with SQL. You can try to use WHERE clause.