Geography functions
Geography functions are used to generate or perform operations on the value of the geography data type.
For descriptions of the geography data types, see Geography.
Descriptions
| Function | Return Type | Description |
|---|---|---|
| ST_Point(longitude, latitude) | GEOGRAPHY | Creates the geography that contains a point. |
| ST_GeogFromText(wkt_string) | GEOGRAPHY | Returns the geography corresponding to the input WKT string. |
| ST_ASText(geography) | STRING | Returns the WKT string of the input geography. |
| ST_Centroid(geography) | GEOGRAPHY | Returns the centroid of the input geography in the form of the single point geography. |
| ST_ISValid(geography) | BOOL | Returns whether the input geography is valid. |
| ST_Intersects(geography_1, geography_2) | BOOL | Returns whether geography_1 and geography_2 have intersections. |
| ST_Covers(geography_1, geography_2) | BOOL | Returns whether geography_1 completely contains geography_2. If there is no point outside geography_1 in geography_2, return True. |
| ST_CoveredBy(geography_1, geography_2) | BOOL | Returns whether geography_2 completely contains geography_1.If there is no point outside geography_2 in geography_1, return True. |
| ST_DWithin(geography_1, geography_2, distance) | BOOL | If the distance between one point (at least) in geography_1 and one point in geography_2 is less than or equal to the distance specified by the distance parameter (measured by meters), return True. |
| ST_Distance(geography_1, geography_2) | FLOAT | Returns the smallest possible distance (measured by meters) between two non-empty geographies. |
| S2_CellIdFromPoint(point_geography) | INT | Returns the S2 Cell ID that covers the point geography. |
| S2_CoveringCellIds(geography) | ARRAY<INT64> | Returns an array of S2 Cell IDs that cover the input geography. |
Examples
nebula> RETURN ST_ASText(ST_Point(1,1));
+--------------------------+
| ST_ASText(ST_Point(1,1)) |
+--------------------------+
| "POINT(1 1)" |
+--------------------------+
nebula> RETURN ST_ASText(ST_GeogFromText("POINT(3 8)"));
+------------------------------------------+
| ST_ASText(ST_GeogFromText("POINT(3 8)")) |
+------------------------------------------+
| "POINT(3 8)" |
+------------------------------------------+
nebula> RETURN ST_ASTEXT(ST_Centroid(ST_GeogFromText("LineString(0 1,1 0)")));
+----------------------------------------------------------------+
| ST_ASTEXT(ST_Centroid(ST_GeogFromText("LineString(0 1,1 0)"))) |
+----------------------------------------------------------------+
| "POINT(0.5000380800773782 0.5000190382261059)" |
+----------------------------------------------------------------+
nebula> RETURN ST_ISValid(ST_GeogFromText("POINT(3 8)"));
+-------------------------------------------+
| ST_ISValid(ST_GeogFromText("POINT(3 8)")) |
+-------------------------------------------+
| true |
+-------------------------------------------+
nebula> RETURN ST_Intersects(ST_GeogFromText("LineString(0 1,1 0)"),ST_GeogFromText("LineString(0 0,1 1)"));
+----------------------------------------------------------------------------------------------+
| ST_Intersects(ST_GeogFromText("LineString(0 1,1 0)"),ST_GeogFromText("LineString(0 0,1 1)")) |
+----------------------------------------------------------------------------------------------+
| true |
+----------------------------------------------------------------------------------------------+
nebula> RETURN ST_Covers(ST_GeogFromText("POLYGON((0 0,10 0,10 10,0 10,0 0))"),ST_Point(1,2));
+--------------------------------------------------------------------------------+
| ST_Covers(ST_GeogFromText("POLYGON((0 0,10 0,10 10,0 10,0 0))"),ST_Point(1,2)) |
+--------------------------------------------------------------------------------+
| true |
+--------------------------------------------------------------------------------+
nebula> RETURN ST_CoveredBy(ST_Point(1,2),ST_GeogFromText("POLYGON((0 0,10 0,10 10,0 10,0 0))"));
+-----------------------------------------------------------------------------------+
| ST_CoveredBy(ST_Point(1,2),ST_GeogFromText("POLYGON((0 0,10 0,10 10,0 10,0 0))")) |
+-----------------------------------------------------------------------------------+
| true |
+-----------------------------------------------------------------------------------+
nebula> RETURN ST_dwithin(ST_GeogFromText("Point(0 0)"),ST_GeogFromText("Point(10 10)"),20000000000.0);
+---------------------------------------------------------------------------------------+
| ST_dwithin(ST_GeogFromText("Point(0 0)"),ST_GeogFromText("Point(10 10)"),20000000000) |
+---------------------------------------------------------------------------------------+
| true |
+---------------------------------------------------------------------------------------+
nebula> RETURN ST_Distance(ST_GeogFromText("Point(0 0)"),ST_GeogFromText("Point(10 10)"));
+----------------------------------------------------------------------------+
| ST_Distance(ST_GeogFromText("Point(0 0)"),ST_GeogFromText("Point(10 10)")) |
+----------------------------------------------------------------------------+
| 1.5685230187677438e+06 |
+----------------------------------------------------------------------------+
nebula> RETURN S2_CellIdFromPoint(ST_GeogFromText("Point(1 1)"));
+---------------------------------------------------+
| S2_CellIdFromPoint(ST_GeogFromText("Point(1 1)")) |
+---------------------------------------------------+
| 1153277837650709461 |
+---------------------------------------------------+
nebula> RETURN S2_CoveringCellIds(ST_GeogFromText("POLYGON((0 1, 1 2, 2 3, 0 1))"));
+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| S2_CoveringCellIds(ST_GeogFromText("POLYGON((0 1, 1 2, 2 3, 0 1))")) |
+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| [1152391494368201343, 1153466862374223872, 1153554823304445952, 1153836298281156608, 1153959443583467520, 1154240918560178176, 1160503736791990272, 1160591697722212352] |
+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------+