Less than or equal to operator (<=)-AnalyticDB(AnalyticDB)-阿里云帮助中心

Compares the universally unique identifiers (UUIDs) of two raster objects and returns true if the UUID of rast1 is less than or equal to the UUID of rast2. Use this operator for internal database operations such as B-tree indexing and union. It does not compare spatial extents or pixel types.

Syntax

bool Operator <=(raster rast1, raster rast2);

Parameters

Parameter	Description
`rast1`	The first raster object.
`rast2`	The second raster object.

Note This operator compares only UUIDs, not spatial extents or pixel types.

Example

To verify that raster objects from two tables joined on a common ID are in the expected UUID order, use the <= operator in a SELECT statement:

SELECT a.rast <= b.rast
FROM tbl_a a, tbl_b b
WHERE a.id = b.id;

Syntax

Parameters

Example

See also