Få midtpunktet af SDO.GEOMETRY polylinjen

Oracle Spatial har en lineær reference pakke kaldet SDO_LRS . Den kan bruges til at finde midtpunktskoordinaterne for en polylinje.

--In this case, 'sdo' is the name of the sdo_geometry column.

sdo_lrs.convert_to_std_geom(sdo_lrs.locate_pt(sdo_lrs.convert_to_lrs_geom(sdo,3)
    ,sdo_geom.sdo_length(sdo,3)/2)).sdo_point.x as midpoint_x,

sdo_lrs.convert_to_std_geom(sdo_lrs.locate_pt(sdo_lrs.convert_to_lrs_geom(sdo,3)
    ,sdo_geom.sdo_length(sdo,3)/2)).sdo_point.y as midpoint_y

For bonuspoint:

Sådan er ESRI's SDE.ST_GEOMETRY kan konverteres til SDO_GEOMETRY med det formål at få midtpunktskoordinaterne:

select
    sdo_lrs.convert_to_std_geom(sdo_lrs.locate_pt(sdo_lrs.convert_to_lrs_geom(sdo,3),sdo_geom.sdo_length(sdo,3)/2)).sdo_point.x as midpoint_x,
    sdo_lrs.convert_to_std_geom(sdo_lrs.locate_pt(sdo_lrs.convert_to_lrs_geom(sdo,3),sdo_geom.sdo_length(sdo,3)/2)).sdo_point.y as midpoint_y
from
    (select
        sdo_util.from_wktgeometry(sde.st_astext(shape)) as sdo
    from
        roads)

Dette svar er inspireret af et svar på Code Review:Beregn midtpunktet af en polylinje .