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    STGeometryTypes: Extracting all geometry type string values from complex geometry
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    STConvertToLineString: Extract LineStrings in GeometryCollection to create LineString
    STLine2Cogo: Converting LineStrings to COGO XML
    STCogo2Line: Creating (Multi)LineStrings geometries from COGO XML instructions
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    TSQL String Tokenizer Function for SQL Server
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    STExtractPolygon: Extract Polygons from result of STIntersection in SQL Server Spatial
    STRound: Function to round ordinates of a SQL Server Spatial geometry object
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    STCentroid*: Alternate Functions for Compute a Centroid
    STRotate: Function to rotate a geometry object in SQL Server Spatial
    STVertices: Wrapper over STDumpPoints
    STMorton: Creating a Morton number Space Key value for grid square
    Gridding a geometry or geography object (SQL Server Denali)
    On hinting spatial indexes
    RandomSearchByExtent: Random Search Procedure (2008 Spatial)
    COGO: Convert DMS String to decimal degrees floating point number.
    COGO: Converting (Google Earth) Formatted Longitude/Latitude points to decimal degrees (SQL Server)
    COGO: Convert Degrees, Minutes and Seconds values to Decimal Degrees
    COGO: DD2DMS Formatting a latitude/longitude decimal degree value
    COGO: Create point from bearing and distance
    COGO: Compute number of vertices required to stroke circle or circular arc
    COGO: Calculating the bearing between two points (SQL Server 2008 Spatial)
    COGO: Compute arc length subtended by angle centre of circle
    COGO: Compute chord length of segment of a circle (arc)
    COGO: Computing Arc To Chord (Arc2Chord) Separation
    COGO: Creating a stroked polygon from a circle's centre x,y and radius
    COGO: Finding centre and radius of a curve defined by three points: FindCircle function
    CheckRadii: Identifying Tight Radius Curves sections within LineString geometry data
    Generating random point data for SQL Server 2008 Spatial
    New Presentation on Active (Searchable) Spatial Metadata for SQL Server 2008 Spatial and FreeText
    STisGeo: Checking if a column in a table or a view is of type geometry or geography
    Vectorising geometry objects in SQL Server 2008
    STMBR2Geometry/STMBR2Geography functions
    Extracting geometry types from geometry/geography objects in SQL Server 2008
    Getting the number of coordinate dimensions of a geometry/geography object in SQL Server 2008
    STDumpPoints: A Function that Dumps the Vertices/Points in a geometry
    toGeography and toGeography Conversion Functions for SQL Server 2008 Spatial
    Write text file with spatial data from SQL Server 2008
    Loading Shapefiles into Geography type column in SQL Server 2008
    Tip #6: Correcting invalid geometries
    Tip #5: Where or where has my little column gone
    Tip #4: What Coordinate System is that?
    Tip #3: What object is that?
    Tip #2: Spatial Indexing and Primary Keys
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All Blog Articles, Data Models and Free Source Code by Simon Greener, The SpatialDB Advisor is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License.

STGeometryTypes: Extracting all geometry type string values from complex geometry

Wednesday May 01 2019 at 16:56

Keywordsextract sub element geometry type geometry collection complex geometry
Summary

Extract sub element geometry types of geometry collection or complex geometry.

Ever needed to extract a textual description of all geometry types in a single geometry/geography in SQL Server 2008 inluding all sub-elements?

Recently I had cause to do so and created the following function that implements this need.

  1. USE [GISDB]  -- Change this to your database
  2. GO
  3. --
  4. -- Extracts all geometry type keywords from a geometry (and its sub-elements)
  5. CREATE FUNCTION [$(owner)].[STGeometryTypes](
  6.   @p_geometry geometry
  7. )
  8.  RETURNS VARCHAR(MAX)
  9. AS
  10. BEGIN
  11.   DECLARE
  12.     @v_return VARCHAR(MAX);
  13.   BEGIN
  14.     IF ( @p_geometry IS NULL )
  15.       RETURN NULL;
  16.     SELECT @v_return = SUBSTRING(a.token,2,LEN(a.token))
  17.       FROM (SELECT (STUFF((SELECT ',' + a.token
  18.                              FROM (SELECT t.token
  19.                                      FROM [$(owner)].[Tokenizer](@p_geometry.AsTextZM(),' ,)(') AS t
  20.                      ) AS a
  21.                             WHERE a.token IS NOT NULL
  22.                               AND a.token NOT LIKE '%[0-9]%'
  23.                            FOR XML PATH(''), TYPE, ROOT
  24.               ).VALUE('root[1]','nvarchar(max)'),1,1,'''')
  25.                     ) AS token
  26.             ) AS a;
  27.     RETURN @v_return;
  28.    END;
  29. END
  30. GO

Now let’s test it against a selection of all possible geometry types

  1. -- Simple geometry
  2. SELECT dbo.[STGeometryTypes](geometry::STGeomFromText('POINT(0 1 2)',0)) AS gtypes;
  3. GO
  4. gtypes
  5. POINT
  6. -- Single CurvePolygon with one interior ring
  7. SELECT [$(owner)].[STGeometryTypes](geometry::STGeomFromText('CURVEPOLYGON(CIRCULARSTRING(0 5, 5 0, 0 -5, -5 0, 0 5), (-2 2, 2 2, 2 -2, -2 -2, -2 2))',0)) AS gtypes;
  8. GO
  9. gtypes
  10. CURVEPOLYGON,CIRCULARSTRING
  11. -- GeometryCollection
  12. SELECT  [$(owner)].[STGeometryTypes](
  13. geometry::STGeomFromText(
  14.          'GEOMETRYCOLLECTION(
  15.                  LINESTRING(0 0,20 0,20 20,0 20,0 0),
  16.                  CURVEPOLYGON(
  17.                       COMPOUNDCURVE(
  18.                               (0 -23.43778, 0 23.43778),
  19.                               CIRCULARSTRING(0 23.43778, -45 23.43778, -90 23.43778),
  20.                               (-90 23.43778, -90 -23.43778),
  21.                               CIRCULARSTRING(-90 -23.43778, -45 -23.43778, 0 -23.43778))),
  22.                  COMPOUNDCURVE(
  23.                          CIRCULARSTRING(-90 -23.43778, -45 -23.43778, 0 -23.43778),
  24.                          (0 -23.43778, 0 23.43778)))',0)) AS gTypes;
  25. GO
  26. gTypes
  27. GEOMETRYCOLLECTION,LINESTRING,CURVEPOLYGON,COMPOUNDCURVE,CIRCULARSTRING,CIRCULARSTRING,COMPOUNDCURVE,CIRCULARSTRING

I hope this function is useful to someone.

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