处理 Rails 中的纬度/经度和 mysql 空间点
关于 mysql 空间数据类型存在大量问题，但我的问题更具体的是如何在 Rails MVC 架构中最好处理它们。
我有一个输入表单，管理员用户可以在其中创建新的兴趣点（例如餐厅）并输入一些信息。 他们还可以以十进制格式输入人类可读的纬度和经度。
但是，对于距离计算等......我将位置数据存储为数据库中的空间点。
因此，我的问题是，如何在 Rails 的 MVC 架构中最好地处理这个问题？
以下是我的一些想法，但似乎没有什么真正干净的：
Call :after_filter 方法，该方法采用对象的新实例并执行处理“GeomFromText('POINT(lat long)' ))”的原始 SQL 更新善良。 问题是“纬度/经度”将是我创建表单中的文本字段，尽管这破坏了 Rails 提供的干净的 form_for :object 架构，因为纬度/经度并不是真正的属性，它们只是为了让不是 mysql 空间的人工输入值。
也许在数据库中创建一个触发器以在更新该行的行插入后运行？ 我不知道，而且这些触发器似乎无法访问纬度/经度，除非我存储纬度/经度以及空间点，然后使用纬度/经度小数在数据库中创建行，然后在创建后运行触发器来更新空间。 我想如果我将纬度/经度列添加到模型中，我也可以使用 after_filter 来做到这一点。
还有其他想法吗？ 我认为存储纬度/经度是多余的，因为我真的会使用空间点进行距离计算等......但如果我允许人工编辑，这可能是必要的。
There have been a decent amount of questions about mysql spatial datatypes, however mine is more specific to how best to deal with them within a rails MVC architecture.
I have an input form where an admin user can create a new point of interest, let's say, a restaurant and input some information. They can also input a human-readable latitude and longitude in decimal format.
However, for distance calculations, etc... I am storing the location data as a spatial point in the database.
My question therefore, is how to best handle this in the MVC architecture in rails?
Here are some ideas I had, but nothing really seems clean:
Call :after_filter method that takes the new instance of the object and does a raw SQL update that handles the "GeomFromText('POINT(lat long)' ))" goodness. The issue with this is that "lat/long" would be text fields in my create form, although this disrupts the clean form_for :object architecture that rails provides since lat/long aren't really attributes, they're just there to let a human input values that aren't mysql spatials.
Maybe creating a trigger in the db to run after a row insert that updates that row? I have no idea and it doesn't seem like these triggers would have access to the lat/long, unless I stored the lat/long as well as the spatial point, and then created the row in the db with the lat/long decimals, and then ran the trigger after creation to update the spatial. I guess i could also do that with an after_filter if I added the lat/long columns to the model.
Any other ideas? I think storing the lat/long is redundant since I'll really be using the spatial point for distance calculations, etc... but it might be necessary if I'm allowing for human editing.
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查看 Rails 的 geokit-rails 插件，它使用普通的 lat/lng 列进行距离计算浮动（并使用 geokit gem）。 但是，如果您想使用数据库的地理空间功能，GeoRuby 支持基本的空间功能，例如Point 或 LineString 作为列类型。 我希望这些有所帮助。
Check out the geokit-rails plugin for Rails which does distance calculations using plain lat/lng columns as floats (and uses the geokit gem). However, if you'd like to use your database's geo-spatial abilities, GeoRuby supports the basic spatial features like Point or LineString as column types. I hope these help.
我同意绝望，geokit很好，我也用它。
如果你想自己做，我会做一个 after_filter 但将更新方法外部化到一个线程。 就像这样，您在保存时不会减慢速度，但仍然有很好的代码和及时更新的列。
触发器不好，数据库应该传递数据而不是执行逻辑。
I agree with hopeless, geokit is nice, I use it too.
If you want to do it yourself, I would do an after_filter but externalize the update method to a thread. Like that you don't have a slow down while saving but still nice code and timely updated columns.
Triggers are not nice, the database should deliver data but not do logic.