Simple Log Service:Geospatial functions

Geospatial concepts

Geospatial functions with the ST_ prefix comply with the SQL/MM standard and the OpenGIS specification from the Open Geospatial Consortium (OGC). These functions use the Well-Known Text (WKT) format to describe geometries, such as points, line strings, and polygons. The following table lists the supported geometries and their WKT formats.

Functions

ST_AsText function

Returns the WKT of a geometry.

Syntax

ST_AsText(x)

Parameters

Return value type

The return type is varchar.

Examples

This example returns the WKT of a point.

• Query statement

  * | SELECT ST_AsText(ST_Point(1,1))

• The query and analysis result is POINT (1 1).

ST_GeometryFromText function

Constructs a geometry from a Well-Known Text (WKT) representation.

Syntax

ST_GeometryFromText(x)

Parameters

Return value type

geometry

Examples

Construct a multipolygon.

• Query statement

  * | SELECT ST_GeometryFromText('multipolygon(((10 10,10 20,20 20,20 15,10 10), (50 40,50 50,60 50,60 40,50 40)))')

• The query returns MULTIPOLYGON (((10 10, 10 20, 20 20, 20 15, 10 10)), ((50 40, 50 50, 60 50, 60 40, 50 40))).

ST_LineFromText function

Creates a line string from WKT text.

Syntax

ST_LineFromText(x)

Parameters

Return value type

linestring type

Examples

Construct a line string.

• Query statement

  * | SELECT ST_LineFromText('linestring(10 10,20 20)')

• Query results: LINESTRING (10 10, 20 20).

ST_Polygon function

The ST_Polygon function creates a polygon from a WKT representation.

Syntax

ST_Polygon(x)

Parameters

Return value type

polygon

Examples

Creates a polygon.

• Query and analysis statement

  * | SELECT ST_Polygon('polygon((10 10,10 20,20 20,20 15,10 10))')

• The result is POLYGON ((10 10, 20 15, 20 20, 10 20, 10 10)).

ST_Point function

Constructs a point from the specified X and Y coordinates.

Syntax

ST_Point(x, y)

Parameters

Return value type

point

Examples

Construct a point.

• Query statement

  * | SELECT ST_Point(0,0)

• The query result is in WKT format: POINT (0 0)

ST_Boundary function

Syntax

ST_Boundary(x)

Parameters

Return value type

geography type

Examples

Use the ST_Polygon function to construct a polygon, and then return its boundary with the ST_Boundary function.

• Query statement

  * | SELECT  ST_Boundary(ST_Polygon('polygon((10 10,10 20,20 20,20 15,10 10))'))

• The query returns LINESTRING (10 10, 20 15, 20 20, 10 20, 10 10).

ST_Buffer function

The ST_Buffer function returns a geometry that encompasses all points within a specified distance from an input geometry.

Syntax

ST_Buffer(x, distance)

Parameters

Return value type

geometry

Examples

This example uses the ST_Point function to construct a point and the ST_Buffer function to create a polygon at a specified distance from that point.

• Query statement

  * | SELECT ST_Buffer(ST_Point(1,1),1)

• The query returns a POLYGON value that approximates a circle. This polygon consists of many coordinate points, starting with (2 1, 1.9978589232386...).

ST_Difference function

Returns a geometry that represents the point-set difference of two geometries.

Syntax

ST_Difference(x, y)

Parameters

Return value type

A geometry value.

Examples

Construct two geometries with the ST_GeometryFromText function, and then calculate their point-set difference with the ST_Difference function.

• Query and analysis statement

  * |
  SELECT
    ST_Difference(
      ST_GeometryFromText(
        'multipolygon (((10 10,10 20,20 20,0 15,0 10), (50 40,50 50,60 50,60 40,50 40)))'
      ),
      ST_GeometryFromText(
        'multipolygon (((10 10,10 20,20 20,20 15,10 10), (50 40,50 50,60 50,60 40,50 50)))'
      )
    ) AS "Difference"

• The query returns the following result: MULTIPOLYGON (((0 10, 10 10, 10 17.5, 0 15, 0 10)), ((50 40, 60 40, 50 50, 50 40))).

ST_Envelope function

Returns the bounding box of a geometry.

Syntax

ST_Envelope(x)

Parameters

Return value type

geometry

Examples

This example creates a geometry with the ST_GeometryFromText function and returns its bounding box with the ST_Envelope function.

• Query and analysis statement

  * |
  SELECT
    ST_Envelope(
      ST_GeometryFromText(
        'multipolygon (((10 10,10 20,20 20,20 15,10 10), (50 40,50 50,60 50,60 40,50 40)))'
      )
    ) 

• The query returns POLYGON ((10 10, 60 10, 60 50, 10 50, 10 10)).

ST_ExteriorRing function

Returns the exterior ring of a geometry as a linestring.

Syntax

ST_ExteriorRing(x)

Parameters

Return value type

geometry

Examples

This example uses ST_GeometryFromText to construct a geometry and ST_ExteriorRing to return its exterior ring.

• Query statement

  * |
  SELECT
    ST_ExteriorRing(
      ST_GeometryFromText(
        'multipolygon (((10 10,10 20,20 20,20 15,10 10), (50 40,50 50,60 50,60 40,50 40)))'
      )
    )

• The query returns LINESTRING (10 10, 10 20, 20 20, 20 15, 10 10).

ST_Intersection

Returns the intersection of two geometries.

Syntax

ST_Intersection(x, y)

Parameters

Return value type

geometry

Examples

This example uses the ST_GeometryFromText function to construct two geometries and the ST_Intersection function to calculate their intersection.

• Query statement

  * |
  SELECT
    ST_Intersection(
      ST_GeometryFromText(
        'multipolygon (((10 10,10 20,20 20,20 15,10 10), (50 40,50 50,60 50,60 40,50 40)))'
      ),
      ST_GeometryFromText(
        'multipolygon (((10 10,10 20,20 20,20 15,10 10), (50 40,50 50,60 50,60 40,50 40)))'
      )
    ) 

• Query results: MULTIPOLYGON (((10 10, 10 20, 20 20, 20 15, 10 10)), ((50 40, 50 50, 60 50, 60 40, 50 40)))

ST_SymDifference function

Returns a geometry representing the symmetric difference of two geometries.

Syntax

ST_SymDifference(x, y)

Parameters

Return value type

geometry

Examples

This example uses the ST_GeometryFromText function to construct two geometries and the ST_SymDifference function to calculate their symmetric difference.

• Query statement

  * |
  SELECT
    ST_SymDifference(
      ST_GeometryFromText(
        'multipolygon (((10 10,10 20,20 20,20 15,10 10), (50 40,50 50,60 50,60 40,50 40)))'
      ),
      ST_GeometryFromText(
        'multipolygon (((10 10,10 20,20 20,20 15,10 10), (50 40,50 50,60 50,60 40,50 40)))'
      )
    )

• The query returns GEOMETRYCOLLECTION EMPTY.

ST_Contains function

ST_Contains returns true if the first geometry contains the second. The two geometries can intersect at their boundaries.

Syntax

ST_Contains(x, y)

Parameters

Return value type

boolean

Examples

This example checks if a polygon contains a point.

• Query statement

  * |
  SELECT
    ST_Contains(
      ST_GeometryFromText(
        'polygon((10 10,10 20,20 20,20 15,10 10))'
      ),
      ST_GeometryFromText(
        'point(11 11)'
      )
    )

• The query returns true.

ST_Crosses function

The ST_Crosses function returns true if two geometries have interior points in common.

Syntax

ST_Crosses(x, y)

Parameters

Return value type

A boolean value.

Examples

This example uses the ST_GeometryFromText function to construct two geometries and the ST_Crosses function to determine if they share interior points.

• Query statement

  * |
  SELECT
    ST_Crosses(
      ST_GeometryFromText(
        'multipolygon (((10 10, 10 20, 20 20, 20 15 , 10 10), (50 40, 50 50, 60 50, 60 40, 50 40)))'
      ),
      ST_GeometryFromText(
        'multipolygon (((10 10, 10 20, 20 20, 20 15 , 10 10), (50 40, 50 50, 60 50, 60 40, 50 50)))'
      )
    )

• The query returns false.

ST_Disjoint

The ST_Disjoint function checks if two geometries are disjoint. It returns true if the geometries do not intersect.

Syntax

ST_Disjoint(x, y)

Parameters

Return value type

boolean

Examples

This example constructs two geometries with ST_GeometryFromText and then uses ST_Disjoint to check whether they intersect.

• Query statement

  * |
  SELECT
     ST_Disjoint(
      ST_GeometryFromText(
        'multipolygon (((10 10,10 20,20 20,20 15,10 10), (50 40,50 50,60 50,60 40,50 40)))'
      ),
      ST_GeometryFromText(
        'multipolygon (((10 10,10 20,20 20,20 15,10 10), (50 40,50 50,60 50,60 40,50 50)))'
      )
    )

• The query returns false.

ST_Equals function

The ST_Equals function determines whether two geometries are identical, returning true if they are.

Syntax

ST_Equals(x, y)

Parameters

Return value type

boolean

Examples

This example uses the ST_GeometryFromText function to construct two geometries and the ST_Equals function to check if they are identical.

• Query statement

  * |
  SELECT
     ST_Equals(
      ST_GeometryFromText(
        'multipolygon(((10 10,10 20,20 20,20 15,10 10),(50 40,50 50,60 50,60 40,50 40)))'
      ),
      ST_GeometryFromText(
        'multipolygon(((10 10,10 20,20 20,20 15,10 10),(50 40,50 50,60 50,60 40,50 50)))'
      )
    )

• The query returns false.

ST_Intersects function

Returns true if the planar projections of two geometries intersect.

Syntax

ST_Intersects(x, y)

Parameters

Return value type

boolean

Examples

Use the ST_GeometryFromText function to construct two geometries, and then use the ST_Intersects function to check if they intersect.

• Sample query

  * |
  SELECT
     ST_Intersects(
      ST_GeometryFromText(
        'multipolygon (((10 10,10 20,20 20,20 15,10 10), (50 40,50 50,60 50,60 40,50 40)))'
      ),
      ST_GeometryFromText(
        'multipolygon (((10 10,10 20,20 20,20 15,10 10), (50 40,50 50,60 50,60 40,50 50)))'
      )
    )

• The query and analysis result is true.

ST_Overlaps function

The ST_Overlaps function returns true if two geometries of the same dimension overlap, but neither completely contains the other.

Syntax

ST_Overlaps(x, y)

Parameters

Return value type

boolean

Examples

This example constructs two geometries using the ST_GeometryFromText function and then checks if they overlap using the ST_Overlaps function.

• Query and analysis statement

  * |
  SELECT
    ST_Overlaps(
      ST_GeometryFromText(
        'multipolygon (((10 10,10 20,20 20,20 15,10 10), (50 40,50 50,60 50,60 40,50 40)))'
      ),
      ST_GeometryFromText(
        'multipolygon (((10 10,10 20,20 20,20 15,10 10), (50 40,50 50,60 50,60 40,50 50)))'
      )
    )

• The query returns false.

ST_Relate function

The ST_Relate function determines if two geometries are related by checking if their interiors or boundaries intersect. It returns true if they are.

Syntax

ST_Relate(x, y, patternMatrix string)

Parameters

Return value type

boolean

Examples

This example constructs two geometries with the ST_GeometryFromText function and then uses the ST_Relate function to check if they are spatially related.

• Query statement

  * |
  SELECT
    ST_Relate(
      ST_GeometryFromText(
        'multipolygon (((10 10,10 20,20 20,20 15,10 10), (50 40,50 50,60 50,60 40,50 40)))'
      ),
      ST_GeometryFromText(
        'multipolygon (((10 10,10 20,20 20,20 15,10 10), (50 40,50 50,60 50,60 40,50 50)))'
      ),  '****T****'
    )

• The query returns true.

ST_Touches function

The ST_Touches function returns true if two geometries touch at their boundaries but their interiors do not intersect.

Syntax

ST_Touches(x, y)

Parameters

Return value type

Returns a boolean value.

Examples

The following query uses the ST_GeometryFromText function to create two geometries and the ST_Touches function to check if they touch.

• Query statement

  * |
  SELECT
     ST_Touches(
      ST_GeometryFromText(
        'multipolygon (((10 10,10 20,20 20,20 15,10 10), (50 40,50 50,60 50,60 40,50 40)))'
      ),
      ST_GeometryFromText(
        'multipolygon (((10 10,10 20,20 20,20 15,10 10), (50 40,50 50,60 50,60 40,50 50)))'
      )
    )

• The query returns false.

ST_Within function

The ST_Within function returns true if the first geometry is completely within the second geometry and their boundaries do not intersect.

Syntax

ST_Within(x, y)

Parameters

Return value type

boolean

Examples

This example constructs two geometries using the ST_GeometryFromText function and then uses the ST_Within function to determine if the first geometry is completely within the second.

• Query and analysis statement

  * |
  SELECT
    ST_Within(
      ST_GeometryFromText(
        'multipolygon (((10 10,10 20,20 20,20 15,10 10), (50 40,50 50,60 50,60 40,50 40)))'
      ),
      ST_GeometryFromText(
        'multipolygon (((10 10,10 20,20 20,20 15,10 10), (50 40,50 50,60 50,60 40,50 50)))'
      )
    )

• The query returns false.

ST_Area function

The ST_Area function calculates the projected area of a geometry on a two-dimensional plane by using Euclidean distance.

Syntax

ST_Area(x)

Parameters

Return value type

double

Examples

This example calculates the area of a multipolygon.

• Query statement

  * |
  SELECT
    ST_Area(
      ST_GeometryFromText(
        'multipolygon (((10 10,10 20,20 20,20 15,10 10), (50 40,50 50,60 50,60 40,50 40)))'
      )
    )

• Returns -25.0.

ST_Centroid function

The ST_Centroid function returns the mathematical centroid of an input geometry as a point.

Syntax

ST_Centroid(x)

Parameters

Return value type

geometry

Examples

This example calculates the centroid of a multipolygon geometry.

• Query and analysis statement

  * |
  SELECT
    ST_Centroid(
      ST_GeometryFromText(
        'multipolygon (((10 10,10 20,20 20,20 15,10 10), (50 40,50 50,60 50,60 40,50 40)))'
      )
    )

• The statement returns POINT (176.66666666666669 131.66666666666669).

ST_CoordDim function

The ST_CoordDim function returns the coordinate dimension of a geometry.

Syntax

ST_CoordDim(x)

Parameters

Return value type

bigint

Examples

Use the ST_GeometryFromText function to construct a geometry and then use the ST_CoordDim function to return its coordinate dimension.

• Query statement

  * |
  SELECT
    ST_CoordDim(
      ST_GeometryFromText(
        'multipolygon (((10 10,10 20,20 20,20 15,10 10), (50 40,50 50,60 50,60 40,50 40)))'
      )
    )

• The query returns 2.

ST_Dimension function

Returns the inherent dimension of a geometry, which cannot exceed the coordinate dimension.

Syntax

ST_Dimension(x)

Parameters

Return value type

bigint

Examples

This example uses ST_Dimension to find the inherent dimension of a geometry created by ST_GeometryFromText.

• Query statement

  * |
  SELECT
    ST_Dimension(
      ST_GeometryFromText(
        'multipolygon (((10 10,10 20,20 20,20 15,10 10), (50 40,50 50,60 50,60 40,50 40)))'
      )
    )

• The query returns 2.

ST_Distance function

Returns the minimum distance between two geometries.

Syntax

ST_Distance(x, y)

Parameters

Return value type

double

Examples

This example uses the ST_GeometryFromText function to create two geometries and the ST_Distance function to calculate the minimum distance between them.

• Query statement

  * |
  SELECT
    ST_Distance(
      ST_GeometryFromText(
        'multipolygon (((10 10,10 20,20 20,20 15,10 10), (50 40,50 50,60 50,60 40,50 50)))'
      ),
      ST_GeometryFromText(
        'multipolygon (((10 10,10 20,20 20,20 15,10 10), (50 40,50 50,60 50,60 40,50 40)))'
      )
    )

• The query result is 0.0.

ST_EndPoint function

ST_EndPoint returns the last point of a line string.

Syntax

ST_EndPoint(x)

Parameters

Return value type

A value of the point type.

Examples

Construct a line string with ST_LineFromText, and then use ST_EndPoint to return the last point.

• Query and analysis statement

  * |
  SELECT
    ST_EndPoint(
      ST_LineFromText(
        'linestring (10 10,20 20)'
      )
    )

• Returns POINT (20 20).

ST_IsClosed

The ST_IsClosed function returns true if a geometry is closed.

Syntax

ST_IsClosed(x)

Parameters

Return value type

A boolean value.

Examples

This example uses ST_LineFromText to construct a line string and ST_IsClosed to check if the line string is closed.

• Query statement

  * |
  SELECT
    ST_IsClosed(
      ST_LineFromText(
        'linestring (10.05 10.28 , 20.95 20.89 )'
      )
    )

• Query result: false

ST_IsEmpty function

The ST_IsEmpty function returns true if the input geometry is empty.

Syntax

ST_IsEmpty(x)

Parameters

Return value type

A boolean value.

Examples

Use the ST_Point function to create a point, and then the ST_IsEmpty function to check if it is empty.

• Query statement

  * | SELECT ST_IsEmpty(ST_Point(1,1))

• The query and analysis results are false.

ST_IsRing function

The ST_IsRing function returns true if the input geometry is a ring (a closed and simple line string).

Syntax

ST_IsRing(x)

Parameters

Return value type

Boolean

Examples

This example constructs a line string with ST_LineFromText and then checks if it is a ring with ST_IsRing.

• Query statement

  * |
  SELECT
    ST_IsRing(
      ST_LineFromText(
        'linestring (10.05 10.28,20.95 20.89 )'
      )
    )

• The query returns false.

ST_Length function

The ST_Length function calculates the 2D projected length of a line string using Euclidean distance. For a multilinestring, it returns the sum of the lengths of the component line strings.

Syntax

ST_Length(x)

Parameters

Return value type

A double value.

Examples

Use ST_LineFromText to construct a line string and ST_Length to calculate its length.

• Query statement

  * |
  SELECT
    ST_Length(
      ST_LineFromText(
        'linestring (10.05 10.28,20.95 20.89)'
      )
    )

• The query returns 15.211249126879752.

ST_NumPoints function

Returns the number of points in a geometry.

Syntax

ST_NumPoints(x)

Parameters

Return value type

bigint

Examples

This example first constructs a line string with the ST_LineFromText function, and then uses the ST_NumPoints function to return the number of points in it.

• Query statement

  * |
  SELECT
    ST_NumPoints(
      ST_LineFromText('linestring (10 10,20 20)')
    )

• Query result: 2

ST_NumInteriorRing function

Returns the number of interior rings in a geometry.

Syntax

ST_NumInteriorRing(x)

Parameters

Return value type

A bigint value.

Examples

This example uses ST_GeometryFromText to construct a geometry and ST_NumInteriorRing to calculate the number of its interior rings.

• Query statement

  * |
  SELECT
    ST_NumInteriorRing(
      ST_GeometryFromText(
        'multipolygon (((10 10,10 20,20 20,20 15,10 10), (50 40,50 50,60 50,60 40,50 40)))'
      )
    )

• The query returns 1.

ST_StartPoint function

Returns the first point of a line string.

Syntax

ST_StartPoint(x)

Parameters

Return value type

point

Examples

This example creates a line string with the ST_LineFromText function and then returns the first point by using the ST_StartPoint function.

• Query statement

  * |
  SELECT
    ST_StartPoint(
      ST_LineFromText(
        'linestring (10 10,20 20 )'
      )
    )

• Query and analysis results: POINT (10 10).

ST_X function

Returns the X-coordinate of an input point.

Syntax

ST_X(x)

Parameters

Return value type

The return type is double.

Examples

This example uses the ST_Point function to construct a point and ST_X to return its X-coordinate.

• Query statement

  * | SELECT ST_X(ST_Point(1,3))

• The query returns 1.0.

ST_XMax function

ST_XMax returns the maximum x-coordinate of a geometry.

Syntax

ST_XMax(x)

Parameters

Return value type

Returns a double.

Examples

Use the ST_GeometryFromText function to construct a geometry, and then use the ST_XMax function to return its maximum x-coordinate.

• Query statement

  * |
  SELECT
    ST_XMax(
      ST_GeometryFromText(
        'multipolygon (((10 10,10 20,20 20,20 15,10 10), (50 40,50 50,60 50,60 40,50 40)))'
      )
    )

• The query returns 60.0.

ST_XMin function

The ST_XMin function returns the minimum x-coordinate of a geometry.

Syntax

ST_XMin(x)

Parameters

Return value type

double

Examples

This example constructs a geometry with the ST_GeometryFromText function and then uses the ST_XMin function to return its minimum x-coordinate.

• Query statement

  * |
  SELECT
    ST_XMin(
      ST_GeometryFromText(
        'multipolygon (((10 10,10 20,20 20,20 15,10 10), (50 40,50 50,60 50,60 40,50 40)))'
      )
    )

• Query results: 10.0

ST_Y function

Returns the y-coordinate of an input point.

Syntax

ST_Y(x)

Parameters

Return value type

A value of the double type.

Examples

This example uses the ST_Point function to create a point and the ST_Y function to retrieve its y-coordinate.

• Query and analysis statement

  * | SELECT ST_Y(ST_Point(1,3))

• Query and analysis results: 3.0

ST_YMax function

The ST_YMax function returns the maximum y-coordinate of a geometry.

Syntax

ST_YMax(x)

Parameters

Return value type

double

Examples

This example constructs a geometry with the ST_GeometryFromText function and returns its maximum y-coordinate with the ST_YMax function.

• Query and analysis statement

  * |
  SELECT
    ST_YMax(
      ST_GeometryFromText(
        'multipolygon (((10 10,10 20,20 20,20 15,10 10), (50 40,50 50,60 50,60 40,50 40)))'
      )
    )

• The query and analysis result is 50.0.

ST_YMin function

Returns the minimum Y-coordinate of a geometry.

Syntax

ST_YMin(x)

Parameters

Return value type

double

Examples

This example uses the ST_GeometryFromText function to construct a geometry and the ST_YMin function to return its minimum Y-coordinate.

• Query and analysis statement

  * |
  SELECT
    ST_YMin(
      ST_GeometryFromText(
        'multipolygon (((10 10,10 20,20 20,20 15,10 10), (50 40,50 50,60 50,60 40,50 40)))'
      )
    )

• The result is 10.0.

bing_tile

The bing_tile function creates a Bing tile.

Syntax

• Creates a Bing tile from an x-coordinate, a y-coordinate, and a zoom level.

  bing_tile(x, y, zoom_level)

• Creates a Bing tile from a quadtree key.

  bing_tile(quadKey)

Parameters

Return value type

Returns a Bing tile.

Examples

• Example 1: Create a Bing tile from an x-coordinate, a y-coordinate, and a zoom level.

  • Query statement

    * | SELECT bing_tile(10, 20, 20)

  • Query and analysis results: {"x":10,"y":20,"zoom":20}

• Example 2: Create a Bing tile from a quadtree key.

  • Query statement

    * | SELECT bing_tile(bing_tile_quadkey(bing_tile(10, 20, 20)))

  • Query and analysis results: {"x":10,"y":20,"zoom":20}

Bing_tile_at function

The bing_tile_at function creates a Bing tile from a latitude, longitude, and zoom level.

Syntax

bing_tile_at(x, y, zoom_level)

Parameters

Return value type

A BingTile object.

Examples

This example creates a Bing tile.

• Query

  * | SELECT bing_tile_at(47.265511, -122.465691, 12)

• The query returns {"x":654,"y":1436,"zoom":12}.

bing_tile_coordinates function

Returns the X- and Y-coordinates of a specified Bing tile.

Syntax

bing_tile_coordinates(x)

Parameters

Return value type

Returns an array of two integers: [X, Y].

Examples

This example retrieves the coordinates for a specified Bing tile.

• Query statement

  * | SELECT bing_tile_coordinates(bing_tile_at(47.265511, -122.465691, 12))

• Result: [654,1436].

bing_tile_polygon

Returns the polygon representation of a Bing tile.

Syntax

bing_tile_polygon(x)

Parameters

Return value type

polygon

Examples

Returns the polygon representation of a Bing tile.

• Query statement

  * | SELECT bing_tile_polygon(bing_tile_at(30.26, 120.19, 12))

• Query result: POLYGON ((120.146484375 30.297017883372042, 120.146484375 30.221101852485987, 120.234375 30.221101852485987, 120.234375 30.297017883372042, 120.146484375 30.297017883372042))

Bing_tile_quadkey

The bing_tile_quadkey function returns the quadtree key for a Bing tile.

Syntax

bing_tile_quadkey(x)

Parameters

Return value type

varchar

Examples

This example converts a tile at coordinates (10, 20) and zoom level 20 into its corresponding quadtree key.

• Query statement

  * | SELECT bing_tile_quadkey(bing_tile(10, 20, 20))

• The query returns the quadtree key 000000000000021210.

bing_tile_zoom_level function

Returns the zoom level of a Bing tile.

Syntax

bing_tile_zoom_level(x)

Parameters

Return value type

double

Examples

The following example calculates the zoom level for a specific Bing tile.

• Query statement

  * | SELECT bing_tile_zoom_level(bing_tile(10, 20, 20))

• Query result: 20.