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

2018/04/12 Otemachi.rb#5での発表資料です。

Transcript

1. 2018/04/12 Otemachi.rb#5 has_one :through
    Shu OGAWARA (@expajp)
2. 35* n /$ .(@expajp) –  &' • 3!2! – Ruby/Rails210, –     -+ – )1#
   "%( – 6+4
3.   
       1 1 n n   
   
      
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5.   
       1 1 n n   
   
      
6.   
       1 1 n n   
   
      
   
    has_many :through
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       1 1 n n   
   
      
   
    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 
   
10. 
    
11. 
    
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     Matter Contact User
14.  
     n N+1 Query n     n 
    matter.main_operator  
15. scope
     n   '   n 1"& 
    # 
    
    %)!( 
    
    
    n $
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    has_one :through
    n 
    through    
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    has_one :through
    n 
    through    
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    has_one :through
    n 
    through " !   n conditions  -> { where(…) } #  
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     n ## $( $ % n has_one :through &%!  " n    '   
    $