huangjian_先进数据库技术08

Boundary() Topological/Set Operators Equal Disjoint Intersect
OGIS SQL中的空间操作
Touch
Within Coutains
Returns true if the boundaries of two surfaces Intersect but the interiors do not
ConvexHull Intersection Union Difference
SymmDiff
Returns the portions of two geometries that do not intersect with each other
空间查询示例

Example database:

Country(Name, Cont, Pop, GDP, Life-Exp, Shape) City(Name, Country, Pop,Capital, Shape) River(Name, Origin, Length, Shape) Keys

Primary keys are , , Foreign keys are River.Origin, City.Country
A Simple Example

INSERT INTO cola_markets VALUES( 2,'cola_b',SDO_GEOMETRY(2003, NULL,NULL, SDO_ELEM_INFO_ARRAY(1,1003,1), -- one polygon (exterior polygon ring) SDO_ORDINATE_ARRAY(5,1, 8,1, 8,6, 5,7, 5,1) )); INSERT INTO cola_markets VALUES( 3,'cola_c', SDO_GEOMETRY(2003, NULL,NULL, SDO_ELEM_INFO_ARRAY(1,1003,1), -- one polygon (exterior polygon ring) SDO_ORDINATE_ARRAY(3,3, 6,3, 6,5, 4,5, 3,3) ));
5. 空间数据库

1 OGIS 空间数据模型 2 Oracle Spatial 3 空间索引
OGIS 空间数据模型

ห้องสมุดไป่ตู้
Open GIS Consortium 开放地理信息协会


致力于GIS互操作 制定Open Geodata Interoperable Specification， 将地理信息系统技术、分布处理技术、面向对象方 法、数据库设计及实时信息获取方法更有效地结合 起来，改变当前GIS模型中特定的应用系统及其功 能与它内部数据模型及数据格式紧密捆绑的现状 OGIS Spatial Data Model，给出对空间数据对象的 抽象数据模型
OGIS 空间数据模型

基类Geometry 及四个子类：

Point, Curve, Surface 和 GeometryCollection

下图展示OGIS的数据类型
OGIS 空间数据模型

空间数据操作分为如下几类:

对所有几何体都有效的

SpatialReference, Envelope, Export, IsSimple, Boundary Equal, Disjoint, Intersect, Touch, Cross, Within, Contains Distance,Buffer,Union, Intersection, ConvexHull, SymDiff
Overlap
Cross
OGIS SQL中的空间操作
Spatial Analysis Distance Returns the shortest distance between two geometries Area Length Buffer Returns the area of a closed geometry such as polygon Returns the length of an arc or line geometry Return a geometry that consists of all points whose distance from the given geometry is less than or equal to the specified distance Returns the smallest convex geometric set enclosing the geometry Returns the geometric intersection of two geometries Returns the geometric union of two geometries Returns the portion of a geometry that does not intersect with another given geometry
Oracle Spatial

Oracle 空间数据库建立在对象-关系数据库技 术基础上，以一组集成的函数和过程实现了对 空间数据的存储、访问和分析。Oracle spatial 由如下内容组成：

方案MDSYS预定义了空间对象类型的存储方法、 语法、语义内容。空间数据模型类同OGIS模型 用于进行各类空间分析和操作的函数、方法及操作 符。类似与OGIS方法 空间对象索引
简单示例

CREATE TABLE cola_markets ( mkt_id NUMBER PRIMARY KEY, name VARCHAR2(32), shape SDO_GEOMETRY); INSERT INTO cola_markets VALUES( 1, 'cola_a', SDO_GEOMETRY( 2003, -- two-dimensional polygon NULL, NULL, SDO_ELEM_INFO_ARRAY(1,1003,3), -- one rectangle (1003 = exterior) SDO_ORDINATE_ARRAY(1,1, 5,7) -- only 2 points needed to -- define rectangle (lower left and upper right) with Cartesiancoordinate data ) );
Returns true if the interior of the given geometry does not intersect with the exterior of another geometry Tests if the given geometry contains another given geometry Returns true if the interiors of the two geometries have nonempty intersection Returns true if the interior of a surface Intersects with a curve

拓扑关系判断


空间数据分析

OGIS SQL中的空间操作
Basic Functions SpatialReference() Envelope() Export() IsEmpty() IsSimple() Returns the underlying coordinate system of the geometry Returns the minimum orthogonal bounding rectangle of the geometry Returns the geometry in a different representation Returns true if the geometry is a null set Returns true if the geometry is simple (no selfintersection) Returns the boundary of the geometry Returns true if the interior and boundary of the two geometries are spatially equal Returns true if the boundaries and interior do not intersect Returns true if the geometries are not disjoint
Buffer and Overlap
Query: The St. Lawrence River can supply water to cities that are within 300 km. List the cities that can use water from the St. Lawrence. SELECT FROM City Ci, River R WHERE Overlap(Ci.Shape, Buffer(R.Shape,300))=1 AND =‘wrence ’
使用了空间操作 Area()
使用Distance
Query: List the GDP and the distance of a country’s capital city to the equator for all countries.
SELECT Co.GDP, Distance(Point(0,Ci.Shape.y),Ci.Shape) AS "Distance" FROM Country Co,City Ci WHERE = Ci.Country AND Ci.Capital =‘Y ’