| 12345678910111213141516171819 | -- This example demonstrates how to use the SE_Is3D function to determine-- if a geometry has three dimensional coordinatesCREATE TABLE threed_test (gid   smallint,                          g1    ST_Geometry);-- Insert a three dim and a two dim coordinatesINSERT INTO threed_test VALUES(   1, ST_PointFromText('point (10 10)',1000));INSERT INTO threed_test VALUES(   1, ST_PointFromText('point z(10.92 10.12 5)',1000));-- The query lists all the columns being 3d or notSELECT gid, SE_Is3D (g1) is_it_3d from threed_test;
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