57 lines
1.8 KiB
Ruby
57 lines
1.8 KiB
Ruby
# See http://doc.gitlab.com/ce/development/migration_style_guide.html
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# for more information on how to write migrations for GitLab.
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class IssuesMovedToIdForeignKey < ActiveRecord::Migration[4.2]
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include Gitlab::Database::MigrationHelpers
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# Set this constant to true if this migration requires downtime.
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DOWNTIME = false
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disable_ddl_transaction!
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class Issue < ActiveRecord::Base
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include EachBatch
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self.table_name = 'issues'
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def self.with_orphaned_moved_to_issues
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if Gitlab::Database.postgresql?
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# Be careful to use a second table here for comparison otherwise we'll null
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# out all rows that don't have id == moved.to_id!
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where('NOT EXISTS (SELECT true FROM issues B WHERE issues.moved_to_id = B.id)')
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.where('moved_to_id IS NOT NULL')
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else
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# MySQL doesn't allow modification of the same table in a subquery,
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# and using a temporary table isn't automatically guaranteed to work
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# due to the MySQL query optimizer. See
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# https://dev.mysql.com/doc/refman/5.7/en/update.html for more
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# details.
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joins('LEFT JOIN issues AS b ON issues.moved_to_id = b.id')
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.where('issues.moved_to_id IS NOT NULL AND b.id IS NULL')
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end
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end
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end
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def up
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Issue.with_orphaned_moved_to_issues.each_batch(of: 100) do |batch|
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batch.update_all(moved_to_id: nil)
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end
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add_concurrent_foreign_key(
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:issues,
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:issues,
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column: :moved_to_id,
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on_delete: :nullify
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)
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# We're using a partial index here so we only index the data we actually
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# care about.
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add_concurrent_index(:issues, :moved_to_id, where: 'moved_to_id IS NOT NULL')
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end
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def down
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remove_foreign_key_without_error(:issues, column: :moved_to_id)
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remove_concurrent_index(:issues, :moved_to_id)
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end
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end
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