Name

ST_LineFromWKB — Creates a LINESTRING from a WKB representation, optionally using a given SRID.

Übersicht

geometry ST_LineFromWKB(bytea WKB);

geometry ST_LineFromWKB(bytea WKB, integer srid);

Beschreibung

The ST_LineFromWKB function takes a Well-Known Binary (WKB) representation of a geometry and an optional Spatial Reference System ID (SRID), and creates a LINESTRING geometry. It is a type-specific geometry factory in SQL.

If an SRID is not specified, it defaults to 0. NULL is returned if the input bytea does not represent a LINESTRING geometry.

[Anmerkung]

OGC SPEC 3.2.6.2 - optionale SRID ist vom Konformitätstest.

[Anmerkung]

If you know all your geometries are LINESTRINGs, it is more efficient to use ST_GeomFromWKB directly. This function calls ST_GeomFromWKB and adds validation that the result is a LINESTRING.

Diese Methode implementiert die OGC Simple Features Implementation Specification for SQL 1.1. s3.2.6.2

Diese Methode setzt die SQL/MM-Spezifikation um. SQL-MM 3: 7.2.9

Beispiele

Code
SELECT ST_LineFromWKB(
    ST_AsBinary(ST_GeomFromText('LINESTRING(1 2,3 4)'))
) AS aline,
ST_LineFromWKB(
    ST_AsBinary(ST_GeomFromText('POINT(1 2)'))
) IS NULL AS null_return;
Ausgabe von Rastern
aline                 | null_return
------------------------------------
LINESTRING(1 2,3 4)  | t
                
Figure
Geometry figure for visual-st-linefromwkb-01