0fc9f9d3e7
DB schema generated by a migration may look different in rails 4 and 5 (because rails 5 may use different default values). For this reason it's important to explicitly set for which rails version a migration was written for. See https://stackoverflow.com/questions/35929869/activerecordmigration-deprecation-warning-asks-for-rails-version-but-im-no/35930912#35930912
18 lines
584 B
Ruby
18 lines
584 B
Ruby
class RemoveDuplicatedKeys < ActiveRecord::Migration[4.2]
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def up
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select_all("SELECT fingerprint FROM #{quote_table_name(:keys)} GROUP BY fingerprint HAVING COUNT(*) > 1").each do |row|
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fingerprint = connection.quote(row['fingerprint'])
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execute(%Q{
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DELETE FROM #{quote_table_name(:keys)}
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WHERE fingerprint = #{fingerprint}
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AND id != (
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SELECT id FROM (
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SELECT max(id) AS id
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FROM #{quote_table_name(:keys)}
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WHERE fingerprint = #{fingerprint}
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) max_ids
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)
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})
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end
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end
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end
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