Descrizione

Constructs a PostGIS geometry from an Extended Well-Known Binary (EWKB) representation.

	Il EWKB non è uno standard OGC ma uno specifico formato di Postgis che include il codice del sistema di riferimento spaziale (SRID).

Miglioramento nella version 2.0.0: introdotto il supporto per superfici poliedriche e TIN.

Questa funzione supporta il 3d e non distrugge gli z-index.

Questo metodo supporta le Curve e le Circular String.

Questa funzione supporta le Polyhedral Surface.

Questa funzione supporta i Triangoli e le Triangulated Irregular Network Surfaces (TIN).

Esempi

This example constructs LINESTRING(-71.160281 42.258729,-71.160837 42.259113,-71.161144 42.25932) in NAD83 longitude/latitude (SRID 4269) from its EWKB representation.

PostgreSQL escape string syntax (E'...') always interprets backslash escapes. Each backslash therefore has to be doubled so that the bytea input parser receives the octal escapes.

SELECT ST_GeomFromEWKB((
    E'\\001\\002\\000\\000\\040\\255\\020\\000\\000\\003\\000\\000\\000\\344\\112\\075' ||
    E'\\013\\102\\312\\121\\300\\156\\303\\050\\010\\036\\041\\105\\100\\047\\277\\105' ||
    E'\\047\\113\\312\\121\\300\\366\\173\\142\\235\\052\\041\\105\\100\\225\\174\\354' ||
    E'\\056\\120\\312\\121\\300\\160\\231\\323\\145\\061\\041\\105\\100'
)::bytea);

0102000020AD10000003000000E44A3D0B42CA51C06EC328081E21454027BF45274BCA51C0F67B629D2A214540957CEC2E50CA51C07099D36531214540

Figure

With standard_conforming_strings enabled (the default), ordinary string literals preserve backslashes. The same EWKB can therefore be written with a single backslash before each octal byte value.

SELECT ST_GeomFromEWKB((
    '\001\002\000\000\040\255\020\000\000\003\000\000\000\344\112\075' ||
    '\013\102\312\121\300\156\303\050\010\036\041\105\100\047\277\105' ||
    '\047\113\312\121\300\366\173\142\235\052\041\105\100\225\174\354' ||
    '\056\120\312\121\300\160\231\323\145\061\041\105\100'
)::bytea);

0102000020AD10000003000000E44A3D0B42CA51C06EC328081E21454027BF45274BCA51C0F67B629D2A214540957CEC2E50CA51C07099D36531214540

Si veda anche

ST_AsBinary, ST_AsEWKB, ST_GeomFromWKB