Returns the predefined NoData value for a specified band of a raster object. If no NoData value is defined for the band, the function returns null.
Syntax
float8 ST_NoData(raster raster_obj, integer band);Parameters
| Parameter | Description |
|---|---|
raster_obj | The raster object. |
band | The band number to query. Band numbering starts at 0. |
Example
Query the NoData value for band 0:
select ST_NoData(raster_obj, 0) from raster_table where id=1;Output:
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0.000If no NoData value has been defined for the band,
ST_NoData returns null. Check for null in downstream logic that filters or masks pixels based on this value.该文章对您有帮助吗？