我正在尝试组合一个查询来查找图中节点 2 公里以内的节点。假设我有一个数据集,标记了纳斯卡线中的一些地理符号:
Name,Latitude,Longitude
Hummingbird,-14.692131,-75.148892
Monkey,-14.706940,-75.138532
Condor,-14.697444,-75.126208
Spider,-14.694145,-75.122381
Spiral,-14.688277,-75.122746
Hands,-14.694459,-75.113881
Tree,-14.693898,-75.114520
Astronaut,-14.745222,-75.079755
Dog,-14.706401,-75.130788
Wing,-14.680309,-75.100385
Parrot,-14.689463,-75.107498
我有一个使用以下命令创建的空间索引:
CREATE INDEX GeoGlyph.index.Location
ON GeoGlyph(Latitude,Longitude) SPATIAL ENGINE LUCENE
现在,我想找到“Hands”字形 2 公里范围内的节点,我可以通过手动输入纬度/经度坐标来输入此查询:
SELECT Name, Latitude, Longitude, $distance AS Distance
FROM GeoGlyph
WHERE [Latitude,Longitude,$spatial]
NEAR [-14.694459,-75.113884,{"maxDistance":2}]
ORDER BY Distance
我得到结果:
+----+------+----------+----------+--------------------+
|# |Name |Latitude |Longitude |Distance |
+----+------+----------+----------+--------------------+
|0 |Hands |-14.694459|-75.113884|5.230883384236603E-6|
|1 |Tree |-14.693897|-75.11446 |0.08836486627516459 |
|2 |Spider|-14.694363|-75.12358 |1.0442063409276094 |
|3 |Spiral|-14.688309|-75.12276 |1.1754176535538237 |
|4 |Condor|-14.698346|-75.128334|1.6149944044266815 |
+----+------+----------+----------+--------------------+
到目前为止,一切都很好。
由于输入坐标有点麻烦,所以我宁愿使用名称字段“Hands”查找 2 公里内的字形。
这就是我目前陷入困境的地方。我想我应该能够使用让块 http://orientdb.com/docs/2.2.x/SQL-Query.html#let-block得到我想要的......但到目前为止我所尝试的方法不起作用:
SELECT *,$distance AS Distance
FROM GeoGlyph
LET $temp = (SELECT * FROM GeoGlyph WHERE Name = "Hands")
WHERE [Latitude,Longitude,$spatial]
NEAR [$temp.Latitude, $temp.Longitude,{"maxDistance":2}]
ORDER BY Distance
有什么建议么?