Geometric
ClickHouse supports data types for representing geographical objects — locations, lands, etc.
See Also
Point
Point is represented by its X and Y coordinates, stored as a Tuple(Float64, Float64).
Example
Query:
CREATE TABLE geo_point (p Point) ENGINE = Memory();
INSERT INTO geo_point VALUES((10, 10));
SELECT p, toTypeName(p) FROM geo_point;
Result:
┌─p───────┬─toTypeName(p)─┐
│ (10,10) │ Point │
└─────────┴───────────────┘
Ring
Ring is a simple polygon without holes stored as an array of points: Array(Point).
Example
Query:
CREATE TABLE geo_ring (r Ring) ENGINE = Memory();
INSERT INTO geo_ring VALUES([(0, 0), (10, 0), (10, 10), (0, 10)]);
SELECT r, toTypeName(r) FROM geo_ring;
Result:
┌─r─────────────────────────────┬─toTypeName(r)─┐
│ [(0,0),(10,0),(10,10),(0,10)] │ Ring │
└───────────────────────────────┴───────────────┘
Polygon
Polygon is a polygon with holes stored as an array of rings: Array(Ring). First element of outer array is the outer shape of polygon and all the following elements are holes.
Example
This is a polygon with one hole:
CREATE TABLE geo_polygon (pg Polygon) ENGINE = Memory();
INSERT INTO geo_polygon VALUES([[(20, 20), (50, 20), (50, 50), (20, 50)], [(30, 30), (50, 50), (50, 30)]]);
SELECT pg, toTypeName(pg) FROM geo_polygon;
Result:
┌─pg────────────────────────────────────────────────────────────┬─toTypeName(pg)─┐
│ [[(20,20),(50,20),(50,50),(20,50)],[(30,30),(50,50),(50,30)]] │ Polygon │
└───────────────────────────────────────────────────────────────┴────────────────┘
MultiPolygon
MultiPolygon consists of multiple polygons and is stored as an array of polygons: Array(Polygon).
Example
This multipolygon consists of two separate polygons — the first one without holes, and the second with one hole:
CREATE TABLE geo_multipolygon (mpg MultiPolygon) ENGINE = Memory();
INSERT INTO geo_multipolygon VALUES([[[(0, 0), (10, 0), (10, 10), (0, 10)]], [[(20, 20), (50, 20), (50, 50), (20, 50)],[(30, 30), (50, 50), (50, 30)]]]);
SELECT mpg, toTypeName(mpg) FROM geo_multipolygon;
Result:
┌─mpg─────────────────────────────────────────────────────────────────────────────────────────────┬─toTypeName(mpg)─┐
│ [[[(0,0),(10,0),(10,10),(0,10)]],[[(20,20),(50,20),(50,50),(20,50)],[(30,30),(50,50),(50,30)]]] │ MultiPolygon │
└─────────────────────────────────────────────────────────────────────────────────────────────────┴─────────────────┘