STIntersect 表示每个点都与每个区域相交 - 需要确认

STIntersect says every point is intersecting every zone - need to confirm

我正在为一个行业团体实施车辆安全计划。该小组提供了 3k+ 地理区域,覆盖了该小组成员的站点。提供的文件是一个 shapefile。我的同事把它提取出来,转换成4326,上传到一个新的数据库中。我使用 IsValidDetailed() 检查了区域。 7 是无效的,但当 MakeValid() 是 运行 时他们自己纠正了。地理 table SaferTogether 已创建空间索引,仅使用自动。

我最初使用以下方法进行测试。这将 运行 每个区域的每个点,我在一个多小时后得到了结果。

INSERT INTO @Intersects (LogId, ogr_fid, NodeId)
SELECT p.LogId, s.ogr_fid, p.NodeId
FROM LogPos p,
     [gis]..safertogether as s
WHERE p.MyPoint.STIntersects(s.geog4326) = 1
and AssembledTime between @PeriodStart and @PeriodEnd

我现在正在测试 27 个日志点的单次行程,我注意到我有 81162 个结果这大致匹配 27 个点 x 3k+ 区域。我不相信每个区域都覆盖每个点。下面的代码是对一趟日志的测试。效率不高。

UPDATE #Logs
SET IsIntersect = 0

SET @Message = 'Detecting Log intersects with Zone ' + CONVERT(VARCHAR(10), @GeographyId) + ':' + @GeographyName
EXEC usp_Log @ProcessName, @Message, @SessionName, @LogInfo, @Section

UPDATE #Logs
SET IsIntersect = 1
WHERE @Geography.STIntersects(MyPoint) = 1

SELECT @rc = COUNT(1)
FROM #Logs WHERE IsIntersect = 1

SET @Message = 'Trip ' + CONVERT(VARCHAR(10), @TripLogId) + ' intersecting points with ' + CONVERT(VARCHAR(10), @GeographyId) + ':' + @GeographyName + ': ' + CONVERT(varchar(10), @rc)
EXEC usp_Log @ProcessName, @Message, @SessionName, @LogDebug, @Section

SET @Message = 'Save intersects with ' + CONVERT(VARCHAR(10), @GeographyId) + ':' + @GeographyName
EXEC usp_Log @ProcessName, @Message, @SessionName, @LogInfo, @Section

INSERT INTO @Intersects (LogId, NodeId, ogr_fid)
SELECT 
    LogId,
    NodeId,
    @GeographyId
FROM #Logs
WHERE IsIntersect = 1

我在这里寻找的是一种可视化区域与点的方法,这样我就可以判断它们是否损坏。我不知道如何比较内置空间结果选项卡中的字段。

问题可能出在将 shapefile(平面地图)数据转换为 SQL 服务器地理(球形)模型时。这些很容易出错并得到倒置的(免费的)多边形,即描述所有地球区域的多边形除了预期的形状。

另请参阅几个类似的案例,它们与 Google BigQuery 一起使用,它使用面向球面的多边形的相似语义:

您可以通过计算多边形的面积来检查多边形是否被正确摄取到数据库中 - 对于倒置的多边形来说,它会很大(大约 5e14 m^2),而对于正确摄取的多边形,您应该会得到合理的结果。

SQL 服务器有 ReorientObject() 反转多边形方向的方法。但是要小心,因为方向与有效性相互作用 - 所以最好在 MakeValid() 之前使用 ReorientObject()。最重要的当然是修复摄取方法。

或者,您可以使用使用平面地图语义的 SQL 服务器 Geometry(而不是 Geography)类型。使用平面数据存在一些问题,但假设您没有交叉 anti-meridian,并且对哪种投影适合哪种计算有基本的了解,您通常应该没问题。

或者切换到使用球形模式但可以正确解释和转换平面数据的数据库。例如。 BigQuery 了解 GeoJson 几何图形是平面的,并且在将它们转换为内部球形地理模型时会忽略它们的方向,因此如果将几何图形加载为 GeoJson 字段,则永远不会遇到此问题。

以下是我使用的最终脚本,以防有人需要帮助。

@Shapes 是一个 table 变量。它被插入填充,然后由游标循环。

@Shape 的每个游标循环都经过有效性测试。如果无效,它有 MakeValid() 运行。然后测试它是否是 MULTIPOLYGON 。如果是,则将其分解为@SubShapes。如果是单个形状,则将该形状分配给第一个@SubShape。

每个@SubShape 都经过验证和面积测试。如果需要,MakeValid()ReorientObject() 是 运行。

在@Shape 的所有@SubShapes 都是运行 之后,如果@Shape 是一个MULTIPOLYGON,它会被放回一起。这是通过 WellKnownText 的字符串连接和操作完成的。这是我最不满意的一点。感觉像是地理上的落差API.

一旦处理完所有的@Shapes,它们就会被写回真实的table

usp_Log_Error 是一个 in-house 记录过程。欢迎评论出来

SET NOCOUNT ON

DECLARE @ProcessName varchar(50) = 'ST_Geography_Validation'
DECLARE @SessionName varchar(50) = 'ST_GV_' + CONVERT(VARCHAR(19), GETDATE(), 126)
DECLARE @Message varchar(1000)

DECLARE @Id int 
DECLARE @Name varchar(254) 
DECLARE @Shape geography
DECLARE @ValidationDetail varchar(200)
DECLARE @ShapeCount int

DECLARE @SubValidationDetail varchar(200)
DECLARE @SubShape geography
Declare @Area float
DECLARE @AreaStr varchar(20)

DECLARE @i int

DECLARE @IsMulti int = 0
DECLARE @MultiWKT varchar(MAX)
DECLARE @SingleWKT varchar(MAX)

DECLARE @Shapes TABLE
(
    Id int,
    Name varchar(254),
    Shape geography
)

INSERT INTO @Shapes (Id, Name, Shape)
SELECT
    ogr_fid,
    name,
    geog4326
FROM safertogether2


DECLARE @SubShapes TABLE
(
    SubId int PRIMARY KEY,
    SubShape geography,
    Processed bit default 0
)

DECLARE _c CURSOR FOR
    SELECT 
        s.Id, 
        s.name, 
        s.Shape,
        0,
        '',
        ''
    FROM @Shapes s

    OPEN _c  
        FETCH NEXT FROM _c INTO @Id, @Name, @Shape, @IsMulti, @MultiWKT, @SingleWKT

        WHILE @@FETCH_STATUS = 0  
        BEGIN

            DELETE FROM @SubShapes

            SET @ValidationDetail = @Shape.IsValidDetailed() -- This is for the base shape
            IF @ValidationDetail <> '24400: Valid'
            BEGIN
                SET @Shape = @Shape.MakeValid()
            END

            SET @ShapeCount = @Shape.STNumGeometries()
            IF @ShapeCount > 1
            BEGIN
                RAISERROR('%i:%s: is MULTIPOLYGON. Break into subshapes.', 0, 1, @Id, @Name) WITH NOWAIT
                SET @IsMulti = 2
                INSERT INTO @SubShapes(SubId, SubShape)
                SELECT 
                    smg.Id,
                    smg.Geog 
                FROM [dbo].uf_SplitMultiGeography(@Shape) smg
            END
            ELSE IF @ShapeCount = 1
            BEGIN 
                RAISERROR('%i:%s: is SINGLE. Insert Shape whole as Id 1.', 0, 1, @Id, @Name) WITH NOWAIT
                SET @IsMulti = 1
                INSERT INTO @SubShapes(SubId, SubShape) 
                VALUES (1, @Shape)
            END
            ELSE
            BEGIN 
                RAISERROR('%i:%s: is NONE.', 0, 1, @Id, @Name) WITH NOWAIT
                SET @IsMulti = 0
            END

            SET @i = 1
            WHILE @i <= @ShapeCount
            BEGIN
                SELECT @SubShape = s.SubShape
                FROM @SubShapes s
                WHERE SubId = @i

                SET @SubValidationDetail = @SubShape.IsValidDetailed()
                RAISERROR('%i:%s:%i: .IsValidDetailed(): %s', 0, 1, @Id, @Name, @i, @SubValidationDetail) WITH NOWAIT

                IF @SubValidationDetail <> '24400: Valid'
                BEGIN
                    RAISERROR('%i:%s:%i: .MakeValid()', 0, 1, @Id, @Name, @i) WITH NOWAIT
                    SET @SubShape = @SubShape.MakeValid() -- This is for the subshape
                END

                BEGIN TRY
                    SET @Area = @SubShape.STArea()
                END TRY
                BEGIN CATCH
                    SET @Message = 'While getting the Area of a subshape'
                    EXEC usp_Log_Error @ProcessName, @SessionName, @Message
                END CATCH
            
                SET @AreaStr = LTRIM(STR(@Area, 20, 5))
                RAISERROR('%i:%s:%i: .STArea(): Pre: %s', 0, 1, @Id, @Name, @i, @AreaStr) WITH NOWAIT
                IF @Area > 510000000000000
                BEGIN
                    RAISERROR('%i:%s:%i: .ReorientObject()', 0, 1, @Id, @Name, @i) WITH NOWAIT
                    SET @SubShape = @SubShape.ReorientObject()
                    SET @Area = @SubShape.STArea()
                    SET @AreaStr = LTRIM(STR(@Area, 20, 5))
                    RAISERROR('%i:%s:%i: .STArea(): Post: %s', 0, 1, @Id, @Name, @i, @AreaStr) WITH NOWAIT
                END

                UPDATE @SubShapes 
                SET SubShape = @SubShape
                WHERE SubId = @Id

                IF @IsMulti = 2
                BEGIN
                    RAISERROR('%i:%s:%i: MULTIPOLYGON member.  Process WKT for recombination', 0, 1, @Id, @Name, @i) WITH NOWAIT
                    BEGIN TRY
                        SET @SingleWKT = @SubShape.STAsText()
                    END TRY
                    BEGIN CATCH
                        SET @Message = 'While getting the WKT of a subshape'
                        EXEC usp_Log_Error @ProcessName, @SessionName, @Message
                    END CATCH

                    SET @SingleWKT = REPLACE(@SingleWKT, 'POLYGON', '')
                    IF (@i <> @ShapeCount)
                    BEGIN
                        SET @SingleWKT = REPLACE(@SingleWKT, '))', ')),')
                    END
                    SET @MultiWKT = @MultiWKT + @SingleWKT
                END
                SET @i = @i + 1
            END

        
            IF @IsMulti = 2
            BEGIN
                RAISERROR('%i:%s: Is a MULTIPOLYGON.  Recreate from updated WKT.', 0, 1, @Id, @Name, @i) WITH NOWAIT
                SET @MultiWKT = 'MULTIPOLYGON(' + @MultiWKT + ')'
                BEGIN TRY
                    SET @Shape = geography::STGeomFromText(@MultiWKT, 4326)
                END TRY
                BEGIN CATCH
                    SET @Message = 'While creating a multipolygon'
                    EXEC usp_Log_Error @ProcessName, @SessionName, @Message
                END CATCH
            END
            ELSE IF @IsMulti = 1
            BEGIN
                RAISERROR('%i:%s: Is SINGLE.  Set Shape to subshape', 0, 1, @Id, @Name, @i) WITH NOWAIT
                SET @Shape = @SubShape
            END
            ELSE
            BEGIN
                RAISERROR('%i:%s: Is NONE.  Set Shape to none', 0, 1, @Id, @Name, @i) WITH NOWAIT
            END

            RAISERROR('%i:%s: Update temp table', 0, 1, @Id, @Name) WITH NOWAIT
            UPDATE @Shapes
            SET Shape = @Shape
            WHERE Id = @Id

            FETCH NEXT FROM _c INTO @Id, @Name, @Shape, @IsMulti, @MultiWKT, @SingleWKT
        END
    CLOSE _c
DEALLOCATE _c

select 
    st.ogr_fid, 
    st.name, 
    st.geog4326 as ShapePre, 
    s.Shape as ShapePost,
    CASE 
        WHEN  st.geog4326.IsValidDetailed() = '24400: Valid' then st.geog4326.STArea()
        ELSE st.geog4326.MakeValid().STArea()
    END as AreaPre,
    CASE 
        WHEN  s.Shape.IsValidDetailed() = '24400: Valid' then s.Shape.STArea()
        ELSE s.Shape.MakeValid().STArea()
    END as AreaPost  
from safertogether2 st
join @Shapes s ON s.Id = st.ogr_fid

RAISERROR('Update back to safertogether table', 0, 1) WITH NOWAIT
UPDATE st
SET geog4326 = s.Shape
FROM @Shapes s
JOIN safertogether2 st ON s.Id = st.ogr_fid


RAISERROR('End of Script', 0, 1, @Id, @Name) WITH NOWAIT