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2010年12月28日

 参考《Oracle Spatial空间信息管理》;Oracle Spatial11g手册

空间操作符

一、主要空间操作符

1SDO_FILTER

SDO_FILTER(geometry1, geometry2, param);

判断两个几何体是否有相交

SELECT c.mkt_id, c.name

 FROM cola_markets c

 WHERE SDO_FILTER(c.shape,

                  SDO_GEOMETRY(2003,

                               NULL,

                               NULL,

                               SDO_ELEM_INFO_ARRAY(1, 1003, 3),

                               SDO_ORDINATE_ARRAY(4, 6, 8, 8))) = 'TRUE';

2SDO_JOIN

SDO_JOIN(table_name1, column_name1, table_name2, column_name2, params,

preserve_join_order) RETURN SDO_ROWIDSET;

 

SELECT /*+ ordered */

 a.name, b.name

 FROM TABLE(SDO_JOIN('COLA_MARKETS',

                      'SHAPE',

                      'COLA_MARKETS',

                      'SHAPE',

                      'mask=ANYINTERACT')) c,

       cola_markets a,

       cola_markets b

 WHERE c.rowid1 = a.rowid

   AND c.rowid2 = b.rowid

 ORDER BY a.name;

3SDO_NN

SDO_NN(geometry1, geometry2, param [, number]);

在指定的距离内,按顺序返回离的最近的。

 

性能调优参数             

sdo_num_res 指定返回离指定点最近的两个市场

sdo_batch_size 指定了一次批量提取多少条记录进行对比

 

SELECT /*+ INDEX(c cola_spatial_idx) */

 c.mkt_id, c.name

 FROM cola_markets c

 WHERE SDO_NN(c.shape,

              sdo_geometry(2001,

                           NULL,

                           sdo_point_type(10, 7, NULL),

                           NULL,

                           NULL),

              'sdo_num_res=2') = 'TRUE';

 

SELECT /*+ INDEX(c cola_spatial_idx) */

 c.mkt_id, c.name

 FROM cola_markets c

 WHERE SDO_NN(c.shape,

              sdo_geometry(2001,

                           NULL,

                           sdo_point_type(10, 7, NULL),

                           NULL,

                           NULL),

              'sdo_batch_size=3') = 'TRUE'

   AND c.name < 'cola_d'

   AND ROWNUM <= 2;

4SDO_NN_DISTANCE

SDO_NN_DISTANCE(number);

Number必须与sdo_nn操作符的最后一个参数保持一致。

 Sdo_nn操作符是通过计算距离来识别客户的,我们可以通过sdo_nn_distance辅助操作符来获取这些距离。

   在使用该操作符时,必须指定一个性能调优参数,sdo_num_ressdo_batch_size,如果不知道如何设置sdo_batch_size的值,就将其设为0,索引会在内部使用合适的值。

SELECT /*+ INDEX(c cola_spatial_idx) */

 c.mkt_id, c.name, SDO_NN_DISTANCE(1) dist

 FROM cola_markets c

 WHERE SDO_NN(c.shape,

              sdo_geometry(2001,

                           NULL,

                           sdo_point_type(10, 7, NULL),

                           NULL,

                           NULL),

              'sdo_num_res=2',

              1) = 'TRUE'

 ORDER BY dist;

5SDO_RELATE

SDO_RELATE(geometry1, geometry2, param);

判断两个几何体的关系

SELECT a.gid

 FROM polygons a, query_polys B

 WHERE B.gid = 1

   AND SDO_RELATE(A.Geometry, B.Geometry, 'mask=touch') = 'TRUE'

UNION ALL

SELECT a.gid

 FROM polygons a, query_polys B

 WHERE B.gid = 1

   AND SDO_RELATE(A.Geometry, B.Geometry, 'mask=coveredby') = 'TRUE';

 

SELECT c.mkt_id, c.name

 FROM cola_markets c

 WHERE SDO_RELATE(c.shape,

                  SDO_GEOMETRY(2003,

                               NULL,

                               NULL,

                               SDO_ELEM_INFO_ARRAY(1, 1003, 3),

                               SDO_ORDINATE_ARRAY(4, 6, 8, 8)),

                  'mask=anyinteract') = 'TRUE';

 

6SDO_WITHIN_DISTANCE

SDO_WITHIN_DISTANCE(geometry1, aGeom, params);

返回与指定点相距指定的距离内的某表的几何对象

SELECT c.name

 FROM cola_markets c

 WHERE SDO_WITHIN_DISTANCE(c.shape,

                           SDO_GEOMETRY(2003,

                                        NULL,

                                        NULL,

                                        SDO_ELEM_INFO_ARRAY(1, 1003, 3),

                                        SDO_ORDINATE_ARRAY(4, 6, 8, 8)),

                           'distance=10') = 'TRUE';

二、关系操作符

语法:

操作符OVERLAPBDYDISJOINT(geometry1, geometry2);

1SDO_ANYINTERACT

2SDO_CONTAINS

3SDO_COVEREDBY

4SDO_COVERS

5SDO_EQUAL

6SDO_INSIDE

7SDO_ON

8SDO_OVERLAPBDYDISJOINT

9SDO_OVERLAPBDYINTERSECT

10SDO_OVERLAPS

11SDO_TOUCH

 

空间函数与操作符的对比

1、 空间操作符使用的表必须有空间索引;

空间操作符执行速度比函数快,因此可以采用操作符的情况下就使用操作符

 

 

posted on 2010-12-28 12:59 蓝紫 阅读(...) 评论(...) 编辑 收藏