Returns the minimum value of a float-type attribute field in a trajectory object.
Syntax
float8 ST_attrFloatMin(trajectory traj, cstring attr_field_name);Parameters
| Parameter | Type | Description |
|---|---|---|
traj | trajectory | The trajectory object. |
attr_field_name | cstring | The name of the attribute field. |
Examples
The following example queries the minimum value of the heading attribute field in a trajectory with 16 leaf points.
SELECT ST_attrFloatMin(
ST_makeTrajectory(
'STPOINT'::leaftype,
'LINESTRING(-179.48077 51.72814,-179.46731 51.74634,-179.46502 51.74934,-179.46183 51.75378,-179.45943 51.75736,-179.45560 51.76273,-179.44845 51.77186,-179.43419 51.78977,-179.41259 51.81643,-179.41001 51.81941,-179.40751 51.82223,-179.40497 51.82505,-179.40242 51.82796,-179.39981 51.83095,-179.39734 51.83398,-179.39499 51.83709)'::geometry,
ARRAY[
'2017-01-15 09:06:39'::timestamp, '2017-01-15 09:13:39',
'2017-01-15 09:14:48', '2017-01-15 09:16:28',
'2017-01-15 09:17:48', '2017-01-15 09:19:48',
'2017-01-15 09:23:19', '2017-01-15 09:30:28',
'2017-01-15 09:34:40', '2017-01-15 09:36:59',
'2017-01-15 09:38:09', '2017-01-15 09:39:18',
'2017-01-15 09:40:40', '2017-01-15 09:47:38',
'2017-01-15 09:48:49', '2017-01-15 21:18:30'
],
'{"leafcount": 16, "attributes": {"heading": {"type": "float", "length": 4, "nullable": false, "value": [23.0,23.0,23.0,23.0,21.0,21.0,72.0,72.0,72.0,72.0,73.0,74.0,73.0,73.0,73.0,73.0]}}}'
),
'heading'
);Output:
st_attrfloatmin
-----------------
21