ST_Distance( ST_Geometry , VARCHAR(128)) method

Syntax

geometry-expression.ST_Distance( ST_Geometry geo2, VARCHAR(128) unit_name)

Parameters

• geo2 – The other geometry value whose distance is to be measured from the geometry-expression.
• unit_name – The units in which the distance should be computed. Defaults to the unit of the spatial reference system. The unit name must match the UNIT_NAME column of a row in the ST_UNITS_OF_MEASURE view where UNIT_TYPE is 'LINEAR'.

Returns

DOUBLE Returns the smallest distance between the geometry-expression and geo2 in the specified linear units of measure. If either geometry-expression or geo2 is empty, then NULL is returned.

Examples

• Example 1 – The following example returns an ordered result set with one row for each shape and the corresponding distance from the point (2,3).

  SELECT ShapeID, ROUND( Shape.ST_Distance( NEW ST_Point( 2, 3 ) ), 2 ) AS dist
  FROM SpatialShapes
  WHERE ShapeID < 17
  ORDER BY dist

  The example returns the following result set:

  ShapeID	dist
  2	0.0
  3	0.0
  5	1.0
  6	1.21
  16	1.41
  1	5.1

  The following example creates points representing Halifax, NS and Waterloo, ON, Canada and uses ST_Distance to find the distance between the two points in miles, returning the result 846. This example assumes that the 'st_geometry_predefined_uom' feature has been installed by the sa_install_feature system procedure. Seesa_install_feature system procedure.

  SELECT ROUND( NEW ST_Point( -63.573566, 44.646244, 4326 )
  .ST_Distance( NEW ST_Point( -80.522372, 43.465187, 4326 )
  , 'Statute mile' ), 0 )

Standards

SQL/MM (ISO/IEC 13249-3: 2006) 5.1.23