Share via

st_removepoint function

Applies to: check marked yes Databricks Runtime 17.1 and above

Important

This feature is in Public Preview.

Removes the n-th point from the input linestring GEOGRAPHY or GEOMETRY.

Syntax

st_removepoint ( geoExpr, indexExpr )

Arguments

  • geoExpr: A GEOGRAPHY or GEOMETRY value representing a linestring.
  • indexExpr: An INTEGER value indicating the 1-based position in the linestring of the point that should be removed.

Returns

A value of type GEOGRAPHY or GEOMETRY, representing the linestring after the point at the indexExpr-th position has been removed.

The SRID value of the output linestring is equal to that of the input GEOGRAPHY or GEOMETRY value.

The dimension of the output linestring is the same as that of the input GEOGRAPHY or GEOMETRY value.

The function returns NULL if any of the inputs is NULL.

Error conditions

  • If the value of geoExpr is not a linestring or is an empty linestring, the function returns ST_INVALID_ARGUMENT.
  • If the absolute value of the value of indexExpr is 0 or larger than the number of points in the linestring, the function returns ST_INVALID_INDEX_VALUE

Examples

-- Returns the linestring after removing the second point counting from the left.
> SELECT st_astext(st_removepoint(st_geomfromtext('LINESTRING(1 2,3 4,5 6)'), 2))
  LINESTRING(1 2,5 6)
-- Returns the linestring after removing the first point counting from the right.
> SELECT st_asewkt(st_removepoint(st_geogfromtext('LINESTRING(1 2,3 4,5 6)'), -1))
  SRID=4326;LINESTRING(1 2,3 4)