ruby on rails - How can I code if I want to avoid n plus one issue? -

i have these 3 models

student has these 3 models such gender, bloodtype, prefecture. , each of them belongs student.

association set in each model files.

in case, how can code if want avoid n + 1 issue?

is this?

@students = student.find(:all).includes.includes(:gender, :blood_type, :prefecture)

you need .includes once, , can rid of find(:all) since rails 3 not require it.

students = student.includes(:gender, :blood_type, :prefecture)

having said that, looks these tables , i'd recommend checking out gem classyenum potential replacement if concerned performance issues.

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