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geokit / geokit-rails

Official Geokit plugin for Rails/ActiveRecord. Provides location-based goodness for your Rails app. Requires the Geokit gem.
MIT License
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Load in SQLite Adapter is Called Inconsistently #120

Open vkoves opened 7 years ago

vkoves commented 7 years ago

Running the app locally, I've had issues where it seems load is not called in the SQLite adapter, as I get the following error once in a while:

SQLite3::SQLException: no such function: least:

I've tracked this down to the adapter, and removing the least just makes the next function error, which makes it seem that the load(klass) in the adapter is not being called.

BagpipesJohnson commented 6 years ago

I know the gem doesn't say that it supports SQLite....but has anyone found a way around this?

dblue commented 5 years ago

Someone on Upwork referenced this question. Here's how I resolved the issue:

Geokit requires SQL functions that are not defined in SQLite3. The Geokit adaptor solves this by using SQLite's create_function (through ActiveRecord) to create the additional functions. However, SQLite's user-defined functions only exist in memory for that particular connection.

Geokit::Adapters::Sqlite3.load is called when the Geokit adapter is initialized but it is separate and independent from the ActiveRecord adapter. So, if the original ActiveRecord is lost (or if a new one is created), the Geokit adapter is oblivious to that.

If you're using Puma (Rail's default server) or some other multithreaded server, the first connection works because the user-defined functions have been declared in SQLite3. BUT, if additional instances are created for other threads, those instances do not have the user-defined functions. And because you have no way of knowing whether the first thread or a subsequent thread is handling the connection, you're subject to intermittent errors regarding the missing user-defined functions. The problem doesn't present in production because you're using a database that saves the user-defined functions.