ST_EraseOverview-PolarDB(PolarDB)-阿里云帮助中心

Fills a rectangular area of a raster object with zeros or a predefined NoData value.

Syntax

raster ST_EraseOverview(raster raster_obj, Box extent, BoxType type, boolean useNodata);

Parameter	Type	Description
`raster_obj`	raster	The raster object to modify.
`extent`	Box	The area to clear, in the format `'((minX,minY),(maxX,maxY))'`.
`type`	BoxType	The coordinate type used to interpret `extent`. Set to `Raster` for pixel coordinates or `World` for world coordinates.
`useNodata`	boolean	Specifies whether to fill the cleared area with the predefined NoData value. If set to `false`, or if no NoData value is defined, the area is filled with `0`.

The following example clears the pixel region from (0,0) to (100,100) in the raster object where id=100, filling it with 0.

SELECT ST_EraseOverview(raster_obj, '((0,0),(100,100))', 'Raster', false)
FROM raster_table
WHERE id = 100;