ST_ZMax — 返回二维或三维边界框或几何图形的Z最大值。
float
ST_ZMax
(
box3d
aGeomorBox2DorBox3D
)
;
返回二维或三维边界框或几何图形的Z最大值。
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虽然该函数仅为box3d定义,但由于自动强制转换,它也适用于box2d和几何值。但是,它不会接受几何体或box2D文本表示,因为它们不会自动转换。 |
This function supports 3d and will not drop the z-index.
This method supports Circular Strings and Curves
SELECT ST_ZMax('BOX3D(1 2 3, 4 5 6)');
st_zmax
-------
6
SELECT ST_ZMax(ST_GeomFromEWKT('LINESTRING(1 3 4, 5 6 7)'));
st_zmax
-------
7
SELECT ST_ZMax('BOX3D(-3 2 1, 3 4 1)' );
st_zmax
-------
1
--Observe THIS DOES NOT WORK because it will try to auto-cast the string representation to a BOX3D
SELECT ST_ZMax('LINESTRING(1 3 4, 5 6 7)');
--ERROR: BOX3D parser - doesn't start with BOX3D(
SELECT ST_ZMax(ST_GeomFromEWKT('CIRCULARSTRING(220268 150415 1,220227 150505 2,220227 150406 3)'));
st_zmax
--------
3