14 lines
409 B
Ruby
14 lines
409 B
Ruby
class CounterCacheOnPostComments < ActiveRecord::Migration
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class Post < ActiveRecord::Base; end
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def self.up
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add_column :posts, :comments_count, :integer, :default => 0
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execute <<SQL if Post.count > 0
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UPDATE posts
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SET posts.comments_count = (SELECT COUNT(*) FROM comments WHERE comments.post_id = posts.id)
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SQL
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end
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def self.down
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remove_column :posts, :comments_count
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end
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end
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