无法使用PostGIS/RGeo保存面

Question

如何使用Rails的PostGIS适配器保存多边形？在我的模型中，我有：

self.rgeo_factory_generator = RGeo::Geos.factory_generator
set_rgeo_factory_for_column(:bounds, RGeo::Geographic.spherical_factory(:srid => 4326))

但是，当我尝试将多边形保存到DB时，它不会引发任何错误，但总是无法存储多边形：

1.9.3p194 :011 > n.bounds = "POLYGON(-149.737965876574 61.1952881991104, -149.71848377896 61.1953198415937, -149.718483761252 61.1952938698801, -149.718483872402 61.1951924591105)"
 => "POLYGON(-149.737965876574 61.1952881991104, -149.71848377896 61.1953198415937, -149.718483761252 61.1952938698801, -149.718483872402 61.1951924591105)" 
1.9.3p194 :012 > n.save
   (0.2ms)  BEGIN
   (0.3ms)  COMMIT
 => true 
1.9.3p194 :013 > n.bounds
 => nil 

我怎么才能让它工作呢？

Answer 1

它是无效的WKT，无法解析的原因有两个：

1. 这里没有戒指。您需要在坐标数组周围添加另一组括号。
2. 环未闭合。重复起点作为终点。

下面是有效的WKT应该是什么样子：

POLYGON((-149.737965876574 61.1952881991104, -149.71848377896 61.1953198415937, -149.718483761252 61.1952938698801, -149.718483872402 61.1951924591105, -149.737965876574 61.1952881991104))

Answer 2

在纯PostGIS中，此多边形将生成geometry contains non-closed rings错误。尝试“关闭”多边形(在末端添加第一个点)