Descrizione

The ST_LineFromWKB function, takes a well-known binary representation of geometry and a Spatial Reference System ID (SRID) and creates an instance of the appropriate geometry type - in this case, a LINESTRING geometry. This function plays the role of the 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.

	OGC SPEC 3.2.6.2 - option SRID is from the conformance suite.

	If you know all your geometries are LINESTRINGs, its more efficient to just use ST_GeomFromWKB. This function just calls ST_GeomFromWKB and adds additional validation that it returns a linestring.

Questo metodo implementa le OGC Simple Features Implementation Specification for SQL 1.1.

s3.2.6.2

Questo metodo implementa la specifica SQL/MM.

SQL-MM 3: 7.2.9

Esempi

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;
aline                            | null_return
------------------------------------------------
010200000002000000000000000000F ... | t
                

Si veda anche

ST_GeomFromWKB, ST_LinestringFromWKB