STS_HasNoSignal function

The STS_HasNoSignal function indicates whether the object has no signal for a specified time range.

Syntax

STS_HasNoSignal(
                        ts           TimeSeries,
                        begin_time   DATETIME YEAR TO FRACTION(5),
                        end_time     DATETIME YEAR TO FRACTION(5))
returns Boolean

ts: The name of the time series.
begin_time: The start of the time range. NULL indicates the time stamp of the first element in the time series.
end_time: The end of the time range. NULL indicates the time stamp of the last element in the time series.

Usage

Run the STS_HasNoSignal function to find out whether an object has no signal for the entire time range. A no signal condition means that the object has missing data but is in the same location.

Returns

t = The object has no signal for the time range.

f = The object does not have a no signal condition for the time range.

An exception = An error.

Example

The following query returns whether any vehicles have a no signal condition between the times of 2014-06-07 20:52:53.00000 and 2014-06-10 16:49:36.00000:

SELECT modid, STS_HasNoSignal(ts_track, 
         '2014-06-07 20:52:53.00000', '2014-06-10 16:49:36.00000') 
         FROM t_vehicle; 

modid                               (expression) 
1001                                          f
1002                                          f 

2 row(s) retrieved.

Neither vehicle has a no signal condition.