Name
ST_IsCollection — 测试几何图形是否为几何图形集合类型。
Synopsis
boolean
ST_IsCollection
(
geometry
g
)
;
描述
退货
TRUE
如果参数的几何类型为几何集合类型。集合类型如下：
-
GEOMETRYCOLLECTION
-
多个{点、面、直线、曲线、曲面}
-
COMPOUNDCURVE
![[Note]](images/note.png)
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此函数用于分析几何图形的类型。这意味着它将返回
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This function supports 3d and will not drop the z-index.
This method supports Circular Strings and Curves
示例
postgis=# SELECT ST_IsCollection('LINESTRING(0 0, 1 1)'::geometry);
st_iscollection
-------------
f
(1 row)
postgis=# SELECT ST_IsCollection('MULTIPOINT EMPTY'::geometry);
st_iscollection
-------------
t
(1 row)
postgis=# SELECT ST_IsCollection('MULTIPOINT((0 0))'::geometry);
st_iscollection
-------------
t
(1 row)
postgis=# SELECT ST_IsCollection('MULTIPOINT((0 0), (42 42))'::geometry);
st_iscollection
-------------
t
(1 row)
postgis=# SELECT ST_IsCollection('GEOMETRYCOLLECTION(POINT(0 0))'::geometry);
st_iscollection
-------------
t
(1 row)