Sql server 2008 r2 具有多个坐标的SQL Linestring-我可以使用每个位置进行距离计算吗？

我正在尝试确定是否可以使用具有多个坐标的LineString，并计算LineString中每个项目与另一个具有坐标的表之间的距离：

我有几个地方需要参观，例如：

   A1 40.7120879 -73.9113197
   A2 40.7828647 -73.9653551
   A3 40.740777  -73.841136

我想找出这些线串位置和我将停在的其他位置之间的距离

B1 40.7029334,-73.6208314
B2 40.7037142,-73.6086649
B3 40.7088981,-73.6137852
B4 40.7133267,-73.6056991
B5 40.7185586,-73.6007205

e、 g

等

---

至少我知道这没有内置函数，但是类似的东西应该会给你你想要的结果

--Index of point on linestring
DECLARE  @i INT = 1

--Output
DECLARE @ResultTable TABLE (LinePointNumber INT, PointID INT, Distance FLOAT)

--Identifier for the individual points
DECLARE @id INT
DECLARE @g GEOGRAPHY

--Linestring
DECLARE @geogcol GEOGRAPHY = (SELECT TOP 1 GeogCol1 FROM SpatialTable)

--loop through each point on the linestring
WHILE @i <= @geogcol.STNumPoints()
BEGIN
  --turn points into geography and loop through the collection
  --if you just cast a float to a varchar it will truncate, so cast to a decimal first to prevent that
  DECLARE pointcursor CURSOR FOR SELECT id, GEOGRAPHY::STPointFromText('POINT(' + CAST(CAST(Longitude AS DECIMAL(15,10)) AS VARCHAR(15)) + ' ' + CAST(CAST(Latitude AS DECIMAL(15,10)) AS VARCHAR(15)) + ')', 4326)
  OPEN pointcursor
  FETCH NEXT FROM pointcursor INTO @id, @g
  WHILE @@FETCH_STATUS = 0
  BEGIN
    --STPointN returns that point, the the distance is STDistance
    INSERT INTO @ResultTable (LinePointNumber, PointID, Distance) VALUES (@i, @id, @g.STDistance(@geogcol.STPointN(@i)))

    FETCH NEXT FROM pointcursor INTO @id, @g
  END
  CLOSE pointcursor
  DEALLOCATE pointcursor
  SET @i = @i + 1
END

SELECT * FROM @ResultTable

---

Hcaelxxam刚刚击败我找到了一个解决方案——并且是本机SQL。无论如何，我已经为你准备好了，就在这里

给定一个

public class MyPoint
{
    public MyPoint(string title, SqlGeography location)
    {
        this.Title = title;
        this.Location = location;
    }

    public string Title { get; set; }

    public SqlGeography Location { get; set; }
}

使用以下代码：

// The line, or route consisting of "waypoints"
        SqlGeography lineString = SqlGeography.STLineFromText(new System.Data.SqlTypes.SqlChars("LINESTRING(40.7120879 -73.9113197, 40.7828647 -73.9653551, 40.740777 -73.841136)"), 4326);

        // A container for all lookups
        List<MyPoint> stopLocations = new List<MyPoint>();

        // A container for all waypoints in the route
        List<MyPoint> wayPoints = new List<MyPoint>();

        // Add the stop locations
        stopLocations.Add(new MyPoint("B1", SqlGeography.Point(-73.6208314, 40.7029334, 4326)));
        stopLocations.Add(new MyPoint("B2", SqlGeography.Point(-73.6086649, 40.7037142, 4326)));
        stopLocations.Add(new MyPoint("B3", SqlGeography.Point(-73.6137852, 40.7088981, 4326)));
        stopLocations.Add(new MyPoint("B4", SqlGeography.Point(-73.6056991, 40.7133267, 4326)));
        stopLocations.Add(new MyPoint("B5", SqlGeography.Point(-73.6007205, 40.7185586, 4326)));

        // Add the waypoints
        for (int i = 1; i < (lineString.STNumPoints() + 1); i++)
        {
            wayPoints.Add(new MyPoint("A" + i, SqlGeography.Point(lineString.STPointN(i).Lat.Value, lineString.STPointN(i).Long.Value, lineString.STSrid.Value)));
        }

        // Join the data (essentially a cross-join) and calculate distances
        var joinAndCalculate = (
            from wp in wayPoints
            from sl in stopLocations
            select new
            {
                WayPointTitle = wp.Title,
                StopLocationTitle = sl.Title,
                DistanceInMetres = wp.Location.STDistance(sl.Location)
            }
            ).OrderBy(x => x.WayPointTitle).ThenBy(x => x.StopLocationTitle)
            .ToList()
                               ;
        // Print to the console, for testing
        foreach (var data in joinAndCalculate)
        {
            Console.WriteLine(data.WayPointTitle + "\t" + data.StopLocationTitle + "\t" + data.DistanceInMetres);
        }

---

如果不是你，它可能会帮助其他人。

它必须是SQL语言，还是你能用c语言回答？在这一点上，我很绝望，所以c会做的：这是非常酷的人，我从来没有在c语言中使用过这个东西，所以看到它这样使用是非常酷的。如果你不介意的话，我有几个问题要问；第一个问题是，当您添加指向STPointN1而不是STPointNi的航路点时，这只是一个错误，还是我误解了您的做法？我的另一个问题是，你知道把这样的东西变成CLR函数有多难吗？我从来没有这样做过，但这似乎是一个完美的用法。@hcaelxxam一点问题也没有。感谢您注意到，应该是i而不是1，所以我已经更新了代码！您必须从1开始，因为所有地理方法都是基于1的索引。从理论上讲，它作为CLR函数实现应该不会太难。我从未尝试过，总是更喜欢使用SQL作为数据存储，并尽可能用c实现业务需求/逻辑。在OP的情况下，如果在SQL direct中首选该解决方案，CLR实际上可能会工作得更好。@hcaelxxam如果您可以实现为CLR函数，我应该补充一点，它可能会提高性能。从性能的角度来看，SQL讨厌游标，但是如果不在SQL之外实现，就很难在没有游标的情况下实现OP想要的东西。感谢您的回复。我一直在做一个ETL过程，其中包括一些与OP非常相似的东西，我必须到处使用游标。如果弄清楚如何在C语言中实现这一点，现在就能提高性能，那么处理所有待办事项数据似乎需要一个多星期的时间，我肯定需要研究一下。一点问题也没有。喜欢这张照片，让我想起了你在老电影中看到的一座非常古老的索桥研究CLR函数绝对值得一试。SQL的强大之处在于它可以处理大型集合，我相信您知道这一点，因此，将其从设计时没有考虑的更为平凡的东西中解放出来，基本上可以提高性能。

public class MyPoint
{
    public MyPoint(string title, SqlGeography location)
    {
        this.Title = title;
        this.Location = location;
    }

    public string Title { get; set; }

    public SqlGeography Location { get; set; }
}

// The line, or route consisting of "waypoints"
        SqlGeography lineString = SqlGeography.STLineFromText(new System.Data.SqlTypes.SqlChars("LINESTRING(40.7120879 -73.9113197, 40.7828647 -73.9653551, 40.740777 -73.841136)"), 4326);

        // A container for all lookups
        List<MyPoint> stopLocations = new List<MyPoint>();

        // A container for all waypoints in the route
        List<MyPoint> wayPoints = new List<MyPoint>();

        // Add the stop locations
        stopLocations.Add(new MyPoint("B1", SqlGeography.Point(-73.6208314, 40.7029334, 4326)));
        stopLocations.Add(new MyPoint("B2", SqlGeography.Point(-73.6086649, 40.7037142, 4326)));
        stopLocations.Add(new MyPoint("B3", SqlGeography.Point(-73.6137852, 40.7088981, 4326)));
        stopLocations.Add(new MyPoint("B4", SqlGeography.Point(-73.6056991, 40.7133267, 4326)));
        stopLocations.Add(new MyPoint("B5", SqlGeography.Point(-73.6007205, 40.7185586, 4326)));

        // Add the waypoints
        for (int i = 1; i < (lineString.STNumPoints() + 1); i++)
        {
            wayPoints.Add(new MyPoint("A" + i, SqlGeography.Point(lineString.STPointN(i).Lat.Value, lineString.STPointN(i).Long.Value, lineString.STSrid.Value)));
        }

        // Join the data (essentially a cross-join) and calculate distances
        var joinAndCalculate = (
            from wp in wayPoints
            from sl in stopLocations
            select new
            {
                WayPointTitle = wp.Title,
                StopLocationTitle = sl.Title,
                DistanceInMetres = wp.Location.STDistance(sl.Location)
            }
            ).OrderBy(x => x.WayPointTitle).ThenBy(x => x.StopLocationTitle)
            .ToList()
                               ;
        // Print to the console, for testing
        foreach (var data in joinAndCalculate)
        {
            Console.WriteLine(data.WayPointTitle + "\t" + data.StopLocationTitle + "\t" + data.DistanceInMetres);
        }