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Rails / ActiveRecord count, size, and length
When trying to be sensitive to n+1 queries and memory usage, knowing the differences between count, size, and length in ActiveRecord is important. It had been a while since I reviewed the usage, and I wanted to ensure that I hadn’t made some bad assumptions along the way that somehow stuck. The reality is that…
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Getting a count of the rows in all of your ActiveRecord models
Warning: Going through ActiveRecord is likely not something you want to do in production unless you have a replica database that your script or your model can point at. See the second part for MySQL and PostgreSQL examples in SQL. How do you enumerate your models? For apps created under Rails 5 app or later,…
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Referencing one trait from another trait in factory_bot
Sometimes you want to DRY up traits by referencing one trait from another trait in factory_bot. I tried searching on “inheriting traits” (that’s just for one factory inheriting traits from another and was in a factory_bot issue in GitHub). I accidentally stumbled upon the answer in a slightly unrelated StackOverflow question about calling a trait…