ST_CircularString(ST_Point,ST_Point,ST

ST_CircularString(ST_Point,ST_Point,ST_Point,...) constructor

Constructs a circularstring value from a list of points in a specified spatial reference system.

Syntax

NEW ST_CircularString(pt1,pt2,pt3[,pt4,...,ptN])

Parameters

Name	Type	Description
pt1	ST_Point	The first point of a segment.
pt2	ST_Point	Any point on the segment between the first and last point.
pt3	ST_Point	The last point of a segment.
pt4,...,ptN	ST_Point	Additional points defining further segments, each starting with the previous end point, passing through the first additional point and ending with the second additional point.

Constructs a circularstring value from a list of points. At least three points must be provided. The first of these three is the start of a segment, the third point is the end of the segment, and the second point is any point on the segment between the first and third point. Additional points can be specified in pairs to add more segments to the circularstring. All of the specified points must have the same SRID. The circularstring is constructed with this common SRID. All of the supplied points must be non-empty and have the same answer for Is3D and IsMeasured. The circularstring is 3D if all of the points are 3D, and the circularstring is measured if all of the points are measured.

Note

By default, ST_CircularString uses the original format for a geometry, if it is available. Otherwise, the internal format is used. For more information about internal and original formats, see STORAGE FORMAT clause, CREATE SPATIAL REFERENCE SYSTEM statement.

Standards and compatibility

Example

The following returns an error: at least three points must be specified.

SELECT NEW ST_CircularString( NEW ST_Point( 0, 0 ), NEW ST_Point( 1, 1 ) )

The following example returns the result CircularString (0 0, 1 1, 2 0).

SELECT NEW ST_CircularString( NEW ST_Point( 0, 0 ), NEW ST_Point( 1, 1 ), NEW ST_Point(2,0) )

The following returns an error: the first segment takes three points, and subsequent segments take two points.

SELECT NEW ST_CircularString( NEW ST_Point( 0, 0 ), NEW ST_Point( 1, 1 ), NEW ST_Point(2,0), NEW ST_Point(1,-1) )

The following example returns the result CircularString (0 0, 1 1, 2 0, 1 -1, 0 0).

SELECT NEW ST_CircularString( NEW ST_Point( 0, 0 ), NEW ST_Point( 1, 1 ), NEW ST_Point(2,0), NEW ST_Point(1,-1), NEW ST_Point( 0, 0 ) )