我想从源表创建一个目标表,它只包含唯一/不同的点,因为在彼此相距1000米半径范围内应该没有点。插入缓冲的GEOGRAPHY将点放入目标表中,不需要重复
这是(使用简化的实体模型临时表)的起点:
IF OBJECT_ID('tempdb..#Source') IS NOT NULL DROP TABLE #Source
IF OBJECT_ID('tempdb..#TargetSeeded') IS NOT NULL DROP TABLE #TargetSeeded
IF OBJECT_ID('tempdb..#TargetEmpty') IS NOT NULL DROP TABLE #TargetEmpty
CREATE TABLE #Source
(
Id INT IDENTITY(1,1) PRIMARY KEY,
Point GEOGRAPHY
)
CREATE TABLE #TargetSeeded
(
Id INT IDENTITY(1,1) PRIMARY KEY,
Point GEOGRAPHY
)
CREATE TABLE #TargetEmpty
(
Id INT IDENTITY(1,1) PRIMARY KEY,
Point GEOGRAPHY
)
DECLARE @Point1 GEOGRAPHY;
DECLARE @Point2 GEOGRAPHY;
DECLARE @Point3 GEOGRAPHY;
DECLARE @Point4 GEOGRAPHY;
DECLARE @PointBufferDistanceInMeters INT;
SET @Point1 = GEOGRAPHY::STPointFromText('POINT(1 52.50)', 4326);
SET @Point2 = GEOGRAPHY::STPointFromText('POINT(1 52.51)', 4326);
SET @Point3 = GEOGRAPHY::STPointFromText('POINT(1 52.52)', 4326);
SET @Point4 = GEOGRAPHY::STPointFromText('POINT(1 52.52)', 4326);
SET @PointBufferDistanceInMeters = 1000;
--SELECT @Point1.STDistance(@Point2);
--SELECT @Point1.STDistance(@Point3);
--SELECT @Point1.STDistance(@Point4);
--SELECT @Point2.STDistance(@Point3);
INSERT INTO #Source
SELECT @Point1
UNION ALL
SELECT @Point2
UNION ALL
SELECT @Point3
UNION ALL
SELECT @Point4
INSERT INTO #TargetSeeded
SELECT @Point1
UNION ALL
SELECT @Point2
CREATE SPATIAL INDEX SpatialIndex ON #Source([Point]);
CREATE SPATIAL INDEX SpatialIndex ON #TargetEmpty([Point]);
CREATE SPATIAL INDEX SpatialIndex ON #TargetSeeded([Point]);
-- Identify Ids to be inserted
SELECT
Id,
Point
FROM #Source WHERE Id NOT IN
(
SELECT
So.Id
FROM #Source AS So
INNER JOIN #TargetSeeded AS Ta
ON So.Point.STDistance(Ta.Point) < @PointBufferDistanceInMeters
)
我可以识别候选能够从#Source插入作为在(IMHO)组为基础的方法有效的方式(?)。我只是不知道如何删除#Source表中的重复项(在上述意义上重复 - 具有1000米的缓冲区)。所以最终,我想将id 3或4插入#TargetSeeded(哪一个不重要)。有任何想法吗?
PS:
这是一个相关子查询的企图可能是一个解决办法:
IF OBJECT_ID('tempdb..#Source') IS NOT NULL DROP TABLE #Source
IF OBJECT_ID('tempdb..#TargetSeeded') IS NOT NULL DROP TABLE #TargetSeeded
IF OBJECT_ID('tempdb..#TargetEmpty') IS NOT NULL DROP TABLE #TargetEmpty
CREATE TABLE #Source
(
Id INT IDENTITY(1,1) PRIMARY KEY,
Point GEOGRAPHY
)
CREATE TABLE #TargetSeeded
(
Id INT IDENTITY(1,1) PRIMARY KEY,
Point GEOGRAPHY
)
CREATE TABLE #TargetEmpty
(
Id INT IDENTITY(1,1) PRIMARY KEY,
Point GEOGRAPHY
)
DECLARE @Point1 GEOGRAPHY;
DECLARE @Point2 GEOGRAPHY;
DECLARE @Point3 GEOGRAPHY;
DECLARE @Point4 GEOGRAPHY;
DECLARE @PointBufferDistanceInMeters INT;
SET @Point1 = GEOGRAPHY::STPointFromText('POINT(1 52.50)', 4326);
SET @Point2 = GEOGRAPHY::STPointFromText('POINT(1 52.51)', 4326);
SET @Point3 = GEOGRAPHY::STPointFromText('POINT(1 52.52)', 4326);
SET @Point4 = GEOGRAPHY::STPointFromText('POINT(1 52.52)', 4326);
SET @PointBufferDistanceInMeters = 1000;
--SELECT @Point1.STDistance(@Point2);
--SELECT @Point1.STDistance(@Point3);
--SELECT @Point1.STDistance(@Point4);
--SELECT @Point2.STDistance(@Point3);
INSERT INTO #Source
SELECT @Point1
UNION ALL
SELECT @Point2
UNION ALL
SELECT @Point3
UNION ALL
SELECT @Point4
INSERT INTO #TargetSeeded
SELECT @Point1
UNION ALL
SELECT @Point2
CREATE SPATIAL INDEX SpatialIndex ON #Source([Point]);
CREATE SPATIAL INDEX SpatialIndex ON #TargetEmpty([Point]);
CREATE SPATIAL INDEX SpatialIndex ON #TargetSeeded([Point]);
-- Identify Ids to be inserted
DELETE FROM #Source WHERE Id NOT IN
(
SELECT
Id
FROM #Source WHERE Id NOT IN
(
SELECT
So.Id
FROM #Source AS So
INNER JOIN #TargetSeeded AS Ta
ON So.Point.STDistance(Ta.Point) < @PointBufferDistanceInMeters
)
)
SELECT
*
FROM #Source o
WHERE o.Id IN
(
SELECT MAX(i.Id)
FROM #Source i
WHERE
i.Point.STDistance(o.Point) < @PointBufferDistanceInMeters
)
也许一个视觉例子会更好。你是否有一个重要的名单,并希望选择点,那些需要1000米的appart,就像试图创建仓库来优化分配过程一样?或者你已经有了这些点,并想要删除每个点缓冲区内的所有点?第一个需要非常大的优化过程,第二个非常容易使用'contains'功能 –
您似乎在检查'#Source'和'#TargetSeeded'行之间的距离。你保证没有任何行_within_'#Source'违反你的1000米规则吗? – HABO
@Habo - 请参阅PS - 相关的子查询尝试 – cs0815