ST_MakeLine

Signature

LINESTRING ST_MakeLine(POINT pointA, POINT pointB, ...);
LINESTRING ST_MakeLine(POINT pointA, MULTIPOINT multipoint, ...);
LINESTRING ST_MakeLine(MULTIPOINT multipoint);
LINESTRING ST_MakeLine(MULTIPOINT multipointA, MULTIPOINT multipointB);
LINESTRING ST_MakeLine(GEOMETRYCOLLECTION points);

Description

Constructs a LINESTRING from the given POINTs or MULTIPOINTs.

This function can be used as a scalar function, to draw a line between POINTs (at least 2), POINTs and MULTIPOINTs, MULTIPOINTs and POINTs, MULTIPOINTs and MULTIPOINTs or GEOMETRYCOLLECTIONs.

It also can be used as an aggregative function in order to draw lines between values listed in a table.

Examples

Scalar function

SELECT ST_MakeLine('POINT(1 2)', 'POINT(4 5)');
-- Answer:     LINESTRING(1 2, 4 5)

SELECT ST_MakeLine('POINT(1 2 3)', 'POINT(4 5 6)');
-- Answer:     LINESTRING(1 2 3, 4 5 6)

SELECT ST_MakeLine('POINT(1 2)', 'MULTIPOINT(4 5, 12 9)');
-- Answer:     LINESTRING(1 2, 4 5, 12 9)

SELECT ST_MakeLine('MULTIPOINT(1 2, 17 6)', 'MULTIPOINT(4 5, 7 9, 18 -1)');
-- Answer:     LINESTRING(1 2, 17 6, 4 5, 7 9, 18 -1)

ST_MakeLine('POINT(1 2)', 'POINT(4 5)', 'POINT(7 8)');
-- Answer:     LINESTRING(1 2, 4 5, 7 8)

SELECT ST_MakeLine('MULTIPOINT(1 2, 3 4)');
-- Answer:     LINESTRING(1 2, 3 4)

Aggregate function

CREATE TABLE input_table(point GEOMETRY(POINT));
INSERT INTO input_table VALUES
     ('POINT(1 2)'),
     ('POINT(3 4)'),
     ('POINT(5 6)'),
     ('POINT(7 8)'),
     ('POINT(9 10)');
SELECT ST_MakeLine(ST_Accum(point)) FROM input_table;
-- Answer:     LINESTRING(1 2, 3 4, 5 6, 7 8, 9 10)

CREATE TABLE input_table(point GEOMETRY);
INSERT INTO input_table VALUES
     ('POINT(5 5)'),
     ('MULTIPOINT(1 2, 7 9, 18 -4)'),
     ('POINT(3 4)'),
     ('POINT(99 3)');
SELECT ST_MakeLine(ST_Accum(point)) FROM input_table;
-- Answer:     LINESTRING(5 5, 1 2, 7 9, 18 -4, 3 4, 99 3)

CREATE TABLE input_table(multi_point GEOMETRY(MULTIPOINT));
INSERT INTO input_table VALUES
     ('MULTIPOINT(5 5, 1 2, 3 4, 99 3)'),
     ('MULTIPOINT(-5 12, 11 22, 34 41, 65 124)'),
     ('MULTIPOINT(1 12, 5 -21, 9 41, 32 124)');
SELECT ST_MakeLine(ST_Accum(multi_point)) FROM input_table;
-- Answer:     LINESTRING(5 5, 1 2, 3 4, 99 3, -5 12, 11 22,
--                        34 41, 65 124, 1 12, 5 -21, 9 41, 32 124)

See also