12.16.4 Functions That Create Geometry Values from WKB Values

Table des matières

These functions take as arguments a BLOB containing a Well-Known Binary (WKB) representation and, optionally, a spatial reference system identifier (SRID). They return the corresponding geometry. For a description of WKB format, see Well-Known Binary (WKB) Format.

Functions in this section detect arguments in either Cartesian or geographic spatial reference systems (SRSs), and return results appropriate to the SRS.

ST_GeomFromWKB() accepts a WKB value of any geometry type as its first argument. Other functions provide type-specific construction functions for construction of geometry values of each geometry type.

Prior to MySQL 8.0, these functions also accepted geometry objects as returned by the functions in Section 12.16.5, “MySQL-Specific Functions That Create Geometry Values”. Geometry arguments are no longer permitted and produce an error. To migrate calls from using geometry arguments to using WKB arguments, follow these guidelines:

Rewrite constructs such as ST_GeomFromWKB(Point(0, 0)) as Point(0, 0).
Rewrite constructs such as ST_GeomFromWKB(Point(0, 0), 4326) as ST_SRID(Point(0, 0), 4326) or ST_GeomFromWKB(ST_AsWKB(Point(0, 0)), 4326).

Unless otherwise specified, functions in this section handle their arguments as follows:

If the WKB or SRID argument is NULL, the return value is NULL.
By default, geographic coordinates (latitude, longitude) are interpreted as in the order specified by the spatial reference system of geometry arguments. An optional options argument may be given to override the default axis order. options consists of a list of comma-separated key=value. The onlypermitted key value is axis-order, with permitted values of lat-long, long-lat and srid-defined (the default).
If the options argument is NULL, the return value is NULL. If the options argument is invalid, an error occurs to indicate why.
If an SRID argument refers to an undefined spatial reference system (SRS), an ER_SRS_NOT_FOUND error occurs.
For geographic SRS geometry arguments, if any argument has a longitude or latitude that is out of range, an error occurs:
- If a longitude value is not in the range (−180, 180], an ER_LONGITUDE_OUT_OF_RANGE error occurs.
- If a latitude value is not in the range [−90, 90], an ER_LATITUDE_OUT_OF_RANGE error occurs.
Ranges shown are in degrees. If an SRS uses another unit, the range uses the corresponding values in its unit. The exact range limits deviate slightly due to floating-point arithmetic.

These functions are available for creating geometries from WKB values:

ST_GeomCollFromWKB(wkb[, srid [, options]]), ST_GeometryCollectionFromWKB(wkb[, srid [, options]])
Constructs a GeometryCollection value using its WKB representation and SRID.
These functions handle their arguments as described in the introduction to this section.
ST_GeomFromWKB(wkb[, srid [, options]]), ST_GeometryFromWKB(wkb[, srid [, options]])
Constructs a geometry value of any type using its WKB representation and SRID.
These functions handle their arguments as described in the introduction to this section.
ST_LineFromWKB(wkb[, srid [, options]]), ST_LineStringFromWKB(wkb[, srid [, options]])
Constructs a LineString value using its WKB representation and SRID.
These functions handle their arguments as described in the introduction to this section.
ST_MLineFromWKB(wkb[, srid [, options]]), ST_MultiLineStringFromWKB(wkb[, srid [, options]])
Constructs a MultiLineString value using its WKB representation and SRID.
These functions handle their arguments as described in the introduction to this section.
ST_MPointFromWKB(wkb[, srid [, options]]), ST_MultiPointFromWKB(wkb[, srid [, options]])
Constructs a MultiPoint value using its WKB representation and SRID.
These functions handle their arguments as described in the introduction to this section.
ST_MPolyFromWKB(wkb[, srid [, options]]), ST_MultiPolygonFromWKB(wkb[, srid [, options]])
Constructs a MultiPolygon value using its WKB representation and SRID.
These functions handle their arguments as described in the introduction to this section.
ST_PointFromWKB(wkb[, srid [, options]])
Constructs a Point value using its WKB representation and SRID.
ST_PointFromWKB() handles its arguments as described in the introduction to this section.
ST_PolyFromWKB(wkb[, srid [, options]]), ST_PolygonFromWKB(wkb[, srid [, options]])
Constructs a Polygon value using its WKB representation and SRID.
These functions handle their arguments as described in the introduction to this section.

Rechercher dans le manuel MySQL

Traduction non disponible

Le manuel MySQL n'est pas encore traduit en français sur l'infobrol. Seule la version anglaise est disponible pour l'instant.

Document créé le 26/06/2006, dernière modification le 26/10/2018
Source du document imprimé : https://www.gaudry.be/mysql-rf-gis-wkb-functions.html

L'infobrol est un site personnel dont le contenu n'engage que moi. Le texte est mis à disposition sous licence CreativeCommons(BY-NC-SA). Plus d'info sur les conditions d'utilisation et sur l'auteur.

Références

Manuel MySQL : https://dev.mysql.com/

Ces références et liens indiquent des documents consultés lors de la rédaction de cette page, ou qui peuvent apporter un complément d'information, mais les auteurs de ces sources ne peuvent être tenus responsables du contenu de cette page.
L'auteur de ce site est seul responsable de la manière dont sont présentés ici les différents concepts, et des libertés qui sont prises avec les ouvrages de référence. N'oubliez pas que vous devez croiser les informations de sources multiples afin de diminuer les risques d'erreurs.

Table des matières Haut