ST_GEOMETRYFROMTEXT
Description
Convert a WKT (Well Known Text) to the corresponding memory geometry
Alias
- ST_GEOMFROMTEXT
Syntax
ST_GEOMETRYFROMTEXT( <wkt>)
Parameters
Parameters | Instructions |
---|---|
<wkt> | The memory form of the graph |
Support WKT Formats
POINT
- A single point in spaceLINESTRING
- A sequence of connected line segmentsPOLYGON
- A closed area defined by one or more rings, requiring at least three distinct points and closed ends.MULTIPOLYGON
- A collection of polygons, requiring polygons in a multipolygon can only share discrete points.
Note
Supported MULTIPOLYGON format parsing since Apache Doris 2.1.10
Return Value
The corresponding geometric storage form of WKB
Returns NULL when the input WKT format does not conform to specifications or when the input is NULL.
Examples
-- POINT example
SELECT ST_AsText(ST_GeometryFromText("POINT (1 1)"));
+-----------------------------------------------+
| ST_AsText(ST_GeometryFromText("POINT (1 1)")) |
+-----------------------------------------------+
| POINT (1 1) |
+-----------------------------------------------+
-- POINT illegal example(too many points)
SELECT ST_AsText(ST_GeometryFromText("POINT (1 1, 2 2)"));
+----------------------------------------------------+
| ST_AsText(ST_GeometryFromText("POINT (1 1, 2 2)")) |
+----------------------------------------------------+
| NULL |
+----------------------------------------------------+
-- LINESTRING example
SELECT ST_AsText(ST_GeometryFromText("LINESTRING (1 1, 2 2)"));
+---------------------------------------------------------+
| st_astext(st_geometryfromtext('LINESTRING (1 1, 2 2)')) |
+---------------------------------------------------------+
| LINESTRING (1 1, 2 2) |
+---------------------------------------------------------+
-- LINESTRING illegal example(too few verteices)
SELECT ST_AsText(ST_GeometryFromText("LINESTRING (1 1)"));
+----------------------------------------------------+
| ST_AsText(ST_GeometryFromText("LINESTRING (1 1)")) |
+----------------------------------------------------+
| NULL |
+----------------------------------------------------+
-- POLYGON example
SELECT ST_AsText(ST_GeometryFromText("POLYGON ((0 0, 1 0, 1 1, 0 1, 0 0))"));
+-----------------------------------------------------------------------+
| ST_AsText(ST_GeometryFromText("POLYGON ((0 0, 1 0, 1 1, 0 1, 0 0))")) |
+-----------------------------------------------------------------------+
| POLYGON ((0 0, 1 0, 1 1, 0 1, 0 0)) |
+-----------------------------------------------------------------------+
-- POLYGON illegal example(not closed end to end)
SELECT ST_AsText(ST_GeometryFromText("POLYGON ((0 0, 1 0, 1 1, 0 1))"));
+------------------------------------------------------------------+
| ST_AsText(ST_GeometryFromText("POLYGON ((0 0, 1 0, 1 1, 0 1))")) |
+------------------------------------------------------------------+
| NULL |
+------------------------------------------------------------------+
-- POLYGON illegal example(too few verteices)
SELECT ST_AsText(ST_GeometryFromText("POLYGON ((0 0, 1 0, 0 0))"));
+-------------------------------------------------------------+
| ST_AsText(ST_GeometryFromText("POLYGON ((0 0, 1 0, 0 0))")) |
+-------------------------------------------------------------+
| NULL |
+-------------------------------------------------------------+
-- MULTIPOLYGON example
SELECT ST_AsText(ST_GeometryFromText("MULTIPOLYGON (((0 0, 1 0, 1 1, 0 1, 0 0)), ((2 2, 3 2, 3 3, 2 3, 2 2)))"));
+-----------------------------------------------------------------------------------------------------------+
| ST_AsText(ST_GeometryFromText("MULTIPOLYGON (((0 0, 1 0, 1 1, 0 1, 0 0)), ((2 2, 3 2, 3 3, 2 3, 2 2)))")) |
+-----------------------------------------------------------------------------------------------------------+
| MULTIPOLYGON (((0 0, 1 0, 1 1, 0 1, 0 0)), ((2 2, 3 2, 3 3, 2 3, 2 2))) |
+-----------------------------------------------------------------------------------------------------------+
-- MULTIPOLYGON example (polygons in multipolygon only share discrete points.)
SELECT ST_AsText(ST_GeometryFromText("MULTIPOLYGON (((0 0, 10 0, 10 10, 0 10, 0 0), (4 4, 6 4, 6 6, 4 6, 4 4)), ((4 5, 5 4, 6 5, 5 6, 4 5)))"));
+------------------------------------------------------------------------------------------------------------------------------------------+
| ST_AsText(ST_GeometryFromText("MULTIPOLYGON (((0 0, 10 0, 10 10, 0 10, 0 0), (4 4, 6 4, 6 6, 4 6, 4 4)), ((4 5, 5 4, 6 5, 5 6, 4 5)))")) |
+------------------------------------------------------------------------------------------------------------------------------------------+
| MULTIPOLYGON (((0 0, 10 0, 10 10, 0 10, 0 0), (4 4, 6 4, 6 6, 4 6, 4 4)), ((4 5, 5 4, 6 5, 5 6, 4 5))) |
+------------------------------------------------------------------------------------------------------------------------------------------+
-- MULTIPOLYGON illegal example(overlap exists)
SELECT ST_AsText(ST_GeometryFromText("MULTIPOLYGON (((0 0, 10 0, 10 10, 0 10, 0 0)), ((10 0, 20 0, 20 10, 10 10, 10 0)))"));
+----------------------------------------------------------------------------------------------------------------------+
| ST_AsText(ST_GeometryFromText("MULTIPOLYGON (((0 0, 10 0, 10 10, 0 10, 0 0)), ((10 0, 20 0, 20 10, 10 10, 10 0)))")) |
+----------------------------------------------------------------------------------------------------------------------+
| NULL |
+----------------------------------------------------------------------------------------------------------------------+
-- input NULL
SELECT ST_AsText(ST_GeometryFromText(NULL));
+--------------------------------------+
| ST_AsText(ST_GeometryFromText(NULL)) |
+--------------------------------------+
| NULL |
+--------------------------------------+