Categories:

Geospatial functions

ST_MAKELINE

Constructs a GEOGRAPHY or GEOMETRY object that represents a line connecting the points in the input objects.

See also:

TO_GEOGRAPHY , TO_GEOMETRY

Syntax

ST_MAKELINE( <geography_expression_1> , <geography_expression_2> )

ST_MAKELINE( <geometry_expression_1> , <geometry_expression_2> )

Arguments

geography_expression_1

A GEOGRAPHY object containing the points to connect. This object must be a Point, MultiPoint, or LineString.

geography_expression_2

A GEOGRAPHY object containing the points to connect. This object must be a Point, MultiPoint, or LineString.

geometry_expression_1

A GEOMETRY object containing the points to connect. This object must be a Point, MultiPoint, or LineString.

geometry_expression_2

A GEOMETRY object containing the points to connect. This object must be a Point, MultiPoint, or LineString.

Returns

The function returns a value of type GEOGRAPHY or GEOMETRY. The value is a LineString that connects all of the points specified by the input GEOGRAPHY or GEOMETRY objects.

Usage notes

  • If an input GEOGRAPHY object contains multiple points, ST_MAKELINE connects all of the points specified in the object.
  • ST_MAKELINE connects the points in the order in which they are specified in the input.
  • For GEOMETRY objects, the function reports an error if the two input GEOMETRY objects have different SRIDs.
  • For GEOMETRY objects, the returned GEOMETRY object has the same SRID as the input.

Examples

GEOGRAPHY examples

The examples in this section display output in WKT format:

alter session set GEOGRAPHY_OUTPUT_FORMAT='WKT';

The following example uses ST_MAKELINE to construct a LineString that connects two Points:

SELECT ST_MAKELINE(
                   TO_GEOGRAPHY('POINT(37.0 45.0)'),
                   TO_GEOGRAPHY('POINT(38.5 46.5)')
                  ) AS line_between_two_points;
+-----------------------------+
| LINE_BETWEEN_TWO_POINTS     |
|-----------------------------|
| LINESTRING(37 45,38.5 46.5) |
+-----------------------------+

The following example constructs a LineString that connects a Point with the points in a MultiPoint:

SELECT ST_MAKELINE(
                   TO_GEOGRAPHY('POINT(-122.306067 37.55412)'),
                   TO_GEOGRAPHY('MULTIPOINT((-122.32328 37.561801), (-122.325879 37.586852))')
                  ) AS line_between_point_and_multipoint;
+-----------------------------------------------------------------------------+
| LINE_BETWEEN_POINT_AND_MULTIPOINT                                           |
|-----------------------------------------------------------------------------|
| LINESTRING(-122.306067 37.55412,-122.32328 37.561801,-122.325879 37.586852) |
+-----------------------------------------------------------------------------+

As demonstrated by the output of the example, ST_MAKELINE connects the points in the order in which they are specified in the input.

The following example constructs a LineString that connects the points in a MultiPoint with another LineString:

SELECT ST_MAKELINE(
                   TO_GEOGRAPHY('MULTIPOINT((-122.32328 37.561801), (-122.325879 37.586852))'),
                   TO_GEOGRAPHY('LINESTRING(-122.306067 37.55412, -122.496691 37.495627)')
                  ) AS line_between_multipoint_and_linestring;
+---------------------------------------------------------------------------------------------------+
| LINE_BETWEEN_MULTIPOINT_AND_LINESTRING                                                            |
|---------------------------------------------------------------------------------------------------|
| LINESTRING(-122.32328 37.561801,-122.325879 37.586852,-122.306067 37.55412,-122.496691 37.495627) |
+---------------------------------------------------------------------------------------------------+

GEOMETRY examples

The examples in this section display output in WKT format:

ALTER SESSION SET GEOMETRY_OUTPUT_FORMAT='WKT';

The first example constructs a line between two Points:

SELECT ST_MAKELINE(
  TO_GEOMETRY('POINT(1.0 2.0)'),
  TO_GEOMETRY('POINT(3.5 4.5)')) AS line_between_two_points;
+-------------------------+
| LINE_BETWEEN_TWO_POINTS |
%-------------------------%
| LINESTRING(1 2,3.5 4.5) |
+-------------------------+

The next example demonstrates creating a LineString that connects points in a MultiPoint with a Point

SELECT ST_MAKELINE(
  TO_GEOMETRY('POINT(1.0 2.0)'),
  TO_GEOMETRY('MULTIPOINT(3.5 4.5, 6.1 7.9)')) AS line_from_point_and_multipoint;
+---------------------------------+
| LINE_FROM_POINT_AND_MULTIPOINT  |
%---------------------------------%
| LINESTRING(1 2,3.5 4.5,6.1 7.9) |
+---------------------------------+

The following example constructs a LineString that connects the points in a MultiPoint with another LineString:

SELECT ST_MAKELINE(
  TO_GEOMETRY('LINESTRING(1.0 2.0, 10.1 5.5)'),
  TO_GEOMETRY('MULTIPOINT(3.5 4.5, 6.1 7.9)')) AS line_from_linestring_and_multipoint;
+------------------------------------------+
| LINE_FROM_LINESTRING_AND_MULTIPOINT      |
%------------------------------------------%
| LINESTRING(1 2,10.1 5.5,3.5 4.5,6.1 7.9) |
+------------------------------------------+