[Oracle] implements map matching in the database

The method to do the map match1 the algorithm procedures

First, we should find the most nearest road to the point from all roads in haerbin;

Second, we should find the most nearest point-to-the-point from the road.

For example, as Figure 1, we'll do the map match for the point O.

First, we choose the most nearest road A by compare the distance between O and A with the distance between O and B.

Second, we choose the most nearest point A3 by compare the distance between O and A1,

The distance between O and A2, the distance between O and A3 with the distance between O and A4.

Figure 1

2 The algorithm code–oracle

Select G.id to Abcid from H_gl G where

Sdo_nn (G.geom,sdo_geometry (2001,8307,sdo_point_type (in_x,in_y, null), Null,null), ' sdo_num_res=1 ') = ' TRUE ';

Select Sdo_lrs.convert_to_lrs_geom (Sdo_lrs.project_pt (G.geom,m.diminfo, Sdo_geometry (3001, 8307,

NULL, Sdo_elem_info_array (1, (), Sdo_ordinate_array (in_x, in_y, NULL))))

V_sql: = ' Update table t set t.road_id= ' | | abcid| | ', T.longtitude_newgps = ' | | V_taxi_pt. Sdo_ordinates (1) | | ',

T.latitude_newgps= ' | | V_taxi_pt. Sdo_ordinates (2) | | ' where t.gpsdata_id = ' | | in_gpsdata_id;

[Oracle] implements map matching in the database