ST_MinY
ST_MinY takes a geometry as an input parameter and returns its minimum Y coordinate.
If the given geometry is null or is empty, then null is returned.
Syntax
Parameter
- geometry
- A value of one of the seven distinct spatial data types for which the minimum Y coordinate is returned.
Return type
DOUBLE
Examples
Example 1
This example
illustrates the use of the ST_MinY function. Three polygons are created
and inserted into the SAMPLE_POLYS table.
SET CURRENT PATH = CURRENT PATH, db2gse;
CREATE TABLE sample_polys (id INTEGER, geometry ST_Polygon);
INSERT INTO sample_polys
VALUES (1, ST_Polygon('polygon zm ((110 120 20 3,
110 140 22 3,
120 130 26 4,
110 120 20 3))', 0) );
INSERT INTO sample_polys
VALUES (2, ST_Polygon('polygon zm ((0 0 40 7,
0 4 35 9,
5 4 32 12,
5 0 31 5,
0 0 40 7))', 0) );
INSERT INTO sample_polys
VALUES (3, ST_Polygon('polygon zm ((12 13 10 16,
8 4 10 12,
9 4 12 11,
12 13 10 16))', 0) );
Example 2
This example finds the minimum
Y coordinate of each polygon in SAMPLE_POLYS.
SELECT id, CAST ( ST_MinY(geometry) AS INTEGER) MIN_Y
FROM sample_polys;
ID MIN_Y
----------- ------------
1 120
2 0
3 4
Example 3
This example finds the minimum
Y coordinate that exists for all polygons in the GEOMETRY column.
SELECT CAST ( MIN ( ST_MinY(geometry) ) AS INTEGER) OVERALL_MIN_Y
FROM sample_polys;
OVERALL_MIN_Y
--------------
0