从T-SQL中的点创建地理折线 [英] Create geography polyline from points in T-SQL

问题描述

我有一个看起来像这样的表模式:

I have a table schema that looks like this:

CREATE TABLE [dbo].[LongAndLats](
[Longitude] [decimal](9, 6) NULL,
[Latitude] [decimal](9, 6) NULL,
[SortOrder] [int] NULL
)

样本数据如下:

如何使用TSQL将这些点转换为地理折线?

How can I convert these points into a geography polyline using TSQL?

推荐答案

请尝试以下操作: (注释:点的顺序对于正确生成线很重要.)

try this: (note: the ordering of the points is important for the line to be generated correctly.)

DECLARE @BuildString NVARCHAR(MAX)
SELECT @BuildString = COALESCE(@BuildString + ',', '') + CAST([Longitude] AS NVARCHAR(50)) + ' ' + CAST([Latitude] AS NVARCHAR(50))
FROM dbo.LongAndLats
ORDER BY SortOrder             

SET @BuildString = 'LINESTRING(' + @BuildString + ')';   
DECLARE @LineFromPoints geography = geography::STLineFromText(@BuildString, 4326);
SELECT @LineFromPoints

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