DocumentDB:ST_DISTANCE函数不适用于'<' (小于)符号 [英] DocumentDB: ST_DISTANCE function does not work with '<' (smaller than) sign

问题描述

我有一个工作正常的查询，如下所示:

I have a perfectly working query that looks as follows:

从位置p WHERE ST_DISTANCE(p.geometry，{'type':'Point'，'coordinates':[52.0826443333333，5.11771783333333]})> 6000中选择p.id>

SELECT p.id FROM place p WHERE ST_DISTANCE(p.geometry, {'type': 'Point', 'coordinates':[52.0826443333333, 5.11771783333333]} ) > 6000

它返回距离地理空间点超过6000 m的文档ID的列表.一切似乎都很好.但是，如果我将>"(大于)符号转为<" (小于)，则不会产生任何结果.有趣的是，如果我将WHERE子句放在SELECT语句中，它的确会返回false/true语句，如下所示:

It returns a list of id's of documents that are more than 6000 m from the geospatial point. Everything seems fine. However, if I turn around the '>' (greater than) sign to '<' (smaller than), it does not give any result. Interestingly, it does return false/true statements if I put the WHERE clause in a SELECT statement, as follows:

SELECT ST_DISTANCE(p.geometry，{'type':'Point'，'coordinates':[52.0826443333333，5.11771783333333]})<来自位置p

SELECT ST_DISTANCE(p.geometry, {'type': 'Point', 'coordinates':[52.0826443333333, 5.11771783333333]}) < 6000 AS result FROM place p

它会按预期生成true和false语句.因此，评估似乎可行，但未返回任何输出.当前，我只是使用后一种解决方法，并选择计算出的距离.但是现在我必须计算其他地方(例如在客户端或存储过程中)一定距离内的点.

It generates both true and false statements as expected. So the evaluation seems to work, but it does not return any output. Currently, I just use this latter work around, and also select the computed distances. But now I have to compute the points that are within a certain distance somewhere else (like on the client side or in a stored procedure).

更新 我使用指定的索引策略进行了测试(多亏了这个示例):

UPDATE I tested with a specified index policy (thanks to this example):

'indexingPolicy':{'includedPaths':[{'path':'/"geometry"/?'，'indexes':[{'kind':'Spatial'，'dataType':'LineString'}] }，{'path':'/'}]}

'indexingPolicy': {'includedPaths': [{'path': '/"geometry"/?', 'indexes': [ {'kind': 'Spatial', 'dataType': 'LineString'}]}, {'path': '/'}]}

这解决了问题.我仍然认为，空间函数确实在大于"而不是小于"上起作用是很奇怪的，但是我认为这是可以解决的.

And that solved the problem. I still think it is odd that the spatial function did work on 'greater than' and not on 'smaller than', but I think it is solved with this.

推荐答案

您应在该字段上指定一个Spatial索引，如下所示:

You should specify a Spatial index on that field like this:

'indexingPolicy': {
    'includedPaths': [
        {
            'path': '/"geometry"/?', 
            'indexes': [ 
               {'kind': 'Spatial', 'dataType': 'LineString'}
            ]
        }, 
        {'path': '/'}
    ]
}

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