【2018/04/12 Otemachi.rb#5】has_one :throughの憂鬱

Transcript

1. 2018/04/12 Otemachi.rb#5 has_one :through
    Shu OGAWARA (@expajp)

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    has_many :through

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    has_one :through
   
    has_many :through

8. has_many :through
        has_ many belongs_ to

    
       has_ many belongs_ to

9. has_one :through
        has_ one belongs_ to

   has_ one belongs_ to 
   

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     Matter Contact User

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     n N+1 Query n    

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    matter.main_operator  

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    # 
    
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    has_one :through
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    through    

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    has_one :through
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    through    

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    has_one :through
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    through " !   n

    conditions  -> { where(…) } #  

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     n ## $( $ % n has_one :through &%!

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