STGeomFromTextPOLYGON

STGeomFromTextPOLYGON is a spatial function used to construct polygon geometry objects from Well-Known Text (WKT) representations. In implementations that provide a polygon-focused variant, STGeomFromTextPOLYGON parses a WKT POLYGON string and returns a polygon geometry, optionally assigning it a spatial reference system identifier (SRID). The function is often described as a polygon-specific wrapper or alias around a more general WKT-to-geometry converter such as STGeomFromText or ST_GeomFromText.

Syntax and parameters

STGeomFromTextPOLYGON(wkt, srid)

- wkt: a string containing a POLYGON in WKT format, for example POLYGON((x1 y1, x2 y2, ..., xn yn, x1 y1)). Polygons may include holes by providing additional linear rings, e.g., POLYGON((outer ring), (hole ring)).

- srid: an optional integer specifying the Spatial Reference Identifier. If omitted, the function may assign a default or unknown SRID, depending on the database system.

Return value

The function returns a polygon geometry corresponding to the input WKT. If the WKT is malformed or not a POLYGON, he function may raise an error or return null, depending on the implementation and error handling settings.

Notes

STGeomFromTextPOLYGON is not universal across all spatial databases; many systems provide a generic STGeomFromText (or ST_GeomFromText) that accepts any valid WKT, including POLYGON. When using a vendor-specific variant, consult the relevant documentation for exact syntax, behavior, and error handling.

See also

STGeomFromText, ST_GeomFromText, WKT, POLYGON, SRID, spatial databases.