Usage
Many UDFs are available to analyze and manipulate spatial data. These functions can be called in SQL statements with Spatial Extender data types. Table 19.3 lists some of the UDFs.
| Function | Description |
|---|---|
| ST_AppendPoint | Extends the curve by a given point |
| ST_AsShape | Returns the Environmental Systems Research Institute (ESRI) shape representation of a geometry |
| ST_AsText | Returns the text representation of a geometry |
| ST_Boundary | Returns the boundary geometry of a geometry |
| ST_Centroid | Returns the geometric center of a geometry |
| ST_ChangePoint | Changes a point in a curve |
| ST_ConvexHull | Returns the convex hull of a geometry |
| ST_CoordDim | Returns the dimensionality of a geometry's coordinates |
| ST_Dimension | Returns the dimensionality of a geometry |
| ST_Disjoint | Returns TRUE if two geometries do not intersect |
| ST_Endpoint | Returns the last point of a curve |
| ST_Envelope | Returns a rectangle that surrounds a geometry |
| ST_Envintersects | Returns a rectangle that surrounds the intersection of two geometries |
| ST_EqualCoordsys | Returns TRUE if two coordinate systems are identical |
| ST_Equals | Returns TRUE if geometries are identical |
| ST_EqualSRS | Returns TRUE if two reference systems are identical |
| ST_ExteriorRing | Returns an exterior ring for a polygon |
| ST_Generalize | Approximates a geometry with a reduced number of points |
| ST_GeometryN | Returns a geometry at an index of a collection |
| ST_GeometryType | Returns the type name of a geometry |
| ST_InteriorRingN | Returns an interior ring for a polygon |
| ST_Intersection | Returns the intersection between two geometries |
| ST_Intersects | Returns TRUE if two geometries intersect |
| ST_Is3d | Returns TRUE if a geometry has a Z coordinate |
| ST_IsClosed | Returns TRUE if a curve is closed |
| ST_IsEmpty | Returns TRUE if a geometry is empty |
| ST_IsMeasured | Returns TRUE if a geometry has an M (measured) coordinate |
| ST_IsRing | Returns TRUE if a curve is a ring |
| ST_IsSimple | Returns TRUE if a geometry is simple such as a point, line, or surface |
| ST_MaxM | Returns the maximum M coordinate of a geometry |
| ST_MaxX | Returns the maximum X coordinate of a geometry |
| ST_MaxY | Returns the maximum Y coordinate of a geometry |
| ST_MaxZ | Returns the maximum Z coordinate of a geometry |
| ST_MBR | Returns the minimum bounding rectangle of a geometry |
| ST_MidPoint | Returns the midpoint of a curve |
| ST_MinM | Returns the minimum M coordinate of a geometry |
| ST_MinX | Returns the minimum X coordinate of a geometry |
| ST_MinY | Returns the minimum Y coordinate of a geometry |
| ST_MinZ | Returns the minimum Z coordinate of a geometry |
| ST_NumLineStrings | Returns the number of lines in a multiline string |
| ST_PointN | Returns the point in the line-string or multipoint at index N |
| ST_PolygonN | Returns the polygon in a multipolygon at index N |
| ST_Relate | Returns TRUE if a geometry meets the conditions of a matrix |
| ST_RemovePoint | Removes a point from a curve |
| ST_SrsName | Returns the spatial reference system name of a geometry |
| ST_ToGeomCol1 | Converts a geometry to a geometry collection |
| ST_ToLineString | Converts a geometry to a line-string |
| ST_ToMultiLine | Converts a geometry to a multiline |
| ST_ToMultiPoint | Converts a geometry to a multipoint |
| ST_ToMultiPolygon | Converts a geometry to a multipolygon |
| ST_ToPoint | Converts a geometry to a point |
| ST_ToPolygon | Converts a geometry to a polygon |
| ST_WKBToSQL | Converts a binary representation of a geometry to a geometry |
| ST_WKTToSQL | Converts a text representation of a geometry to a geometry |
..................Content has been hidden....................
You can't read the all page of ebook, please click here login for view all page.