ST_Length

Definition

ST_Length returns the length of a line string or multiline string.

Syntax

sde.st_length (ln1 sde.st_geometry)
sde.st_length (mln1 sde.st_geometry)

Return type

Double precision

Example

A local ecologist studying the migratory patterns of the salmon population in the county's waterways wants the length of all stream and river systems within the county.

The waterways table is created with the ID and name columns, which identify each stream and river system stored in the table. The water column is a multilinestring because the river and stream systems are often aggregates of several linestrings.

CREATE TABLE waterways (oid integer, name varchar(128), water sde.st_geometry);

INSERT INTO waterways (oid, name, water) 
VALUES (
1111,
'Genesee', 
sde.st_multilinestring ('multilinestring ((33 2, 34 3, 35 6),
(28 4, 29 5, 31 8, 43 12), (39 3, 37 4, 36 7))', 0)
);

The query returns the name of each system along with the length of the system generated by the ST_Length function.

Oracle

SELECT name, sde.st_length (water) "Length"
FROM WATERWAYS;

NAME	Length

Genesee	27.6437123

PostgreSQL

SELECT name AS "Waterway Name", sde.st_length (water) 
AS "Length"
FROM waterways;

Waterway Name	 |  Length

Genesee	       | 27.6437123387202