The = operator checks whether two raster objects have the same universally unique identifier (UUID). It returns a Boolean value.
Syntax
bool Operator =(raster rast1, raster rast2);Parameters
| Parameter | Description |
|---|---|
rast1 | The raster object 1. |
rast2 | The raster object 2. |
Usage notes
Compares only the UUIDs of the two raster objects — not their spatial extents or pixel types.
This operator is used only for operations such as union and B-tree.
Example
The following query checks whether each pair of matched rows from tbl_a and tbl_b contains raster objects with the same UUID:
SELECT a.rast = b.rast
FROM tbl_a a, tbl_b b
WHERE a.id = b.id;该文章对您有帮助吗？