从几何类型生成带有X和Y的视图 [英] Generate view with X and Y from geometry type

问题描述

在sql-server -2012 我想生成包含几何类型所有点的视图.我怎样才能做到这一点? 查看示例

In sql-server-2012 I want to generate view with all points from geometry type. How can I do this? View example

GeomKey | X  | Y
--------+----+-----
 1      | X1 | Y1
 1      | x2 | Y2
 2      | x1 | Y1

Oracle中带有sys.SDO的示例

Example in Oracle with sys.SDO

select c.ngeometrykey,  z.* 
from gis_map.mp_geometry c ,    
table(sdo_util.getvertices(c.geometry)) z 

推荐答案

我认为您不能在视图中执行此操作，但是可以创建一个表值用户定义函数(一个返回表的函数)来获取你想要什么.

I don't think you can do this in a view but you can create a table-valued user defined function (a function that returns a table) to get what you want.

此示例使用的表定义为

CREATE TABLE GeoTable (GeomKey int, vector GEOMETRY)

存储不同的几何类型(在下面链接的示例中，我使用了POINT，MULTIPOINT，LINESTRING和POLYGON).

which stores different geometry types (in the example I linked below I used POINT, MULTIPOINT, LINESTRING and POLYGON).

CREATE FUNCTION dbo.GetVertices()
RETURNS @ret TABLE (GeomKey INT, X INT, Y INT, PointNo INT)
AS
BEGIN
    DECLARE @max INT
    SET @max = (SELECT MAX(vector.STNumPoints()) FROM GeoTable) 

    ;WITH Sequence(Number) AS
    (
        SELECT 1 AS Number
        UNION ALL
        SELECT Number + 1
        FROM Sequence
        WHERE Number < @max
    )
    INSERT INTO @ret 
    SELECT
        gt.GeomKey
        ,gt.vector.STPointN(nums.number).STX AS X
        ,gt.vector.STPointN(nums.number).STY AS Y
        ,nums.number AS PointNo
    FROM GeoTable gt, Sequence nums
    WHERE nums.number <= gt.vector.STNumPoints()
    RETURN
END;

有关完整的工作示例，请参见示例SQL Fiddle .

See this sample SQL Fiddle for a complete working example.

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