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) |
+------------------------------------------+