1324 lines
49 KiB
Ruby
1324 lines
49 KiB
Ruby
# frozen_string_literal: true
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module Gitlab
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module Database
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module MigrationHelpers
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include Migrations::BackgroundMigrationHelpers
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# https://www.postgresql.org/docs/current/sql-syntax-lexical.html#SQL-SYNTAX-IDENTIFIERS
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MAX_IDENTIFIER_NAME_LENGTH = 63
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PERMITTED_TIMESTAMP_COLUMNS = %i[created_at updated_at deleted_at].to_set.freeze
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DEFAULT_TIMESTAMP_COLUMNS = %i[created_at updated_at].freeze
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# Adds `created_at` and `updated_at` columns with timezone information.
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#
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# This method is an improved version of Rails' built-in method `add_timestamps`.
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#
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# By default, adds `created_at` and `updated_at` columns, but these can be specified as:
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#
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# add_timestamps_with_timezone(:my_table, columns: [:created_at, :deleted_at])
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#
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# This allows you to create just the timestamps you need, saving space.
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#
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# Available options are:
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# :default - The default value for the column.
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# :null - When set to `true` the column will allow NULL values.
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# The default is to not allow NULL values.
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# :columns - the column names to create. Must be one
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# of `Gitlab::Database::MigrationHelpers::PERMITTED_TIMESTAMP_COLUMNS`.
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# Default value: `DEFAULT_TIMESTAMP_COLUMNS`
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#
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# All options are optional.
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def add_timestamps_with_timezone(table_name, options = {})
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options[:null] = false if options[:null].nil?
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columns = options.fetch(:columns, DEFAULT_TIMESTAMP_COLUMNS)
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default_value = options[:default]
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validate_not_in_transaction!(:add_timestamps_with_timezone, 'with default value') if default_value
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columns.each do |column_name|
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validate_timestamp_column_name!(column_name)
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# If default value is presented, use `add_column_with_default` method instead.
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if default_value
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add_column_with_default(
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table_name,
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column_name,
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:datetime_with_timezone,
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default: default_value,
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allow_null: options[:null]
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)
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else
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add_column(table_name, column_name, :datetime_with_timezone, options)
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end
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end
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end
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# To be used in the `#down` method of migrations that
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# use `#add_timestamps_with_timezone`.
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#
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# Available options are:
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# :columns - the column names to remove. Must be one
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# Default value: `DEFAULT_TIMESTAMP_COLUMNS`
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#
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# All options are optional.
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def remove_timestamps(table_name, options = {})
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columns = options.fetch(:columns, DEFAULT_TIMESTAMP_COLUMNS)
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columns.each do |column_name|
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remove_column(table_name, column_name)
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end
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end
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# Creates a new index, concurrently
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#
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# Example:
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#
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# add_concurrent_index :users, :some_column
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#
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# See Rails' `add_index` for more info on the available arguments.
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def add_concurrent_index(table_name, column_name, options = {})
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if transaction_open?
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raise 'add_concurrent_index can not be run inside a transaction, ' \
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'you can disable transactions by calling disable_ddl_transaction! ' \
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'in the body of your migration class'
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end
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options = options.merge({ algorithm: :concurrently })
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if index_exists?(table_name, column_name, options)
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Rails.logger.warn "Index not created because it already exists (this may be due to an aborted migration or similar): table_name: #{table_name}, column_name: #{column_name}" # rubocop:disable Gitlab/RailsLogger
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return
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end
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disable_statement_timeout do
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add_index(table_name, column_name, options)
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end
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end
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# Removes an existed index, concurrently
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#
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# Example:
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#
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# remove_concurrent_index :users, :some_column
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#
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# See Rails' `remove_index` for more info on the available arguments.
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def remove_concurrent_index(table_name, column_name, options = {})
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if transaction_open?
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raise 'remove_concurrent_index can not be run inside a transaction, ' \
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'you can disable transactions by calling disable_ddl_transaction! ' \
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'in the body of your migration class'
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end
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options = options.merge({ algorithm: :concurrently })
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unless index_exists?(table_name, column_name, options)
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Rails.logger.warn "Index not removed because it does not exist (this may be due to an aborted migration or similar): table_name: #{table_name}, column_name: #{column_name}" # rubocop:disable Gitlab/RailsLogger
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return
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end
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disable_statement_timeout do
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remove_index(table_name, options.merge({ column: column_name }))
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end
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end
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# Removes an existing index, concurrently
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#
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# Example:
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#
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# remove_concurrent_index :users, "index_X_by_Y"
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#
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# See Rails' `remove_index` for more info on the available arguments.
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def remove_concurrent_index_by_name(table_name, index_name, options = {})
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if transaction_open?
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raise 'remove_concurrent_index_by_name can not be run inside a transaction, ' \
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'you can disable transactions by calling disable_ddl_transaction! ' \
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'in the body of your migration class'
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end
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index_name = index_name[:name] if index_name.is_a?(Hash)
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raise 'remove_concurrent_index_by_name must get an index name as the second argument' if index_name.blank?
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options = options.merge({ algorithm: :concurrently })
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unless index_exists_by_name?(table_name, index_name)
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Rails.logger.warn "Index not removed because it does not exist (this may be due to an aborted migration or similar): table_name: #{table_name}, index_name: #{index_name}" # rubocop:disable Gitlab/RailsLogger
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return
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end
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disable_statement_timeout do
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remove_index(table_name, options.merge({ name: index_name }))
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end
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end
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# Adds a foreign key with only minimal locking on the tables involved.
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#
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# This method only requires minimal locking
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#
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# source - The source table containing the foreign key.
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# target - The target table the key points to.
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# column - The name of the column to create the foreign key on.
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# on_delete - The action to perform when associated data is removed,
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# defaults to "CASCADE".
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# name - The name of the foreign key.
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#
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# rubocop:disable Gitlab/RailsLogger
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def add_concurrent_foreign_key(source, target, column:, on_delete: :cascade, name: nil, validate: true)
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# Transactions would result in ALTER TABLE locks being held for the
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# duration of the transaction, defeating the purpose of this method.
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if transaction_open?
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raise 'add_concurrent_foreign_key can not be run inside a transaction'
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end
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options = {
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column: column,
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on_delete: on_delete,
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name: name.presence || concurrent_foreign_key_name(source, column)
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}
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if foreign_key_exists?(source, target, options)
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warning_message = "Foreign key not created because it exists already " \
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"(this may be due to an aborted migration or similar): " \
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"source: #{source}, target: #{target}, column: #{options[:column]}, "\
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"name: #{options[:name]}, on_delete: #{options[:on_delete]}"
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Rails.logger.warn warning_message
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else
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# Using NOT VALID allows us to create a key without immediately
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# validating it. This means we keep the ALTER TABLE lock only for a
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# short period of time. The key _is_ enforced for any newly created
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# data.
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with_lock_retries do
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execute <<-EOF.strip_heredoc
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ALTER TABLE #{source}
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ADD CONSTRAINT #{options[:name]}
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FOREIGN KEY (#{options[:column]})
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REFERENCES #{target} (id)
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#{on_delete_statement(options[:on_delete])}
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NOT VALID;
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EOF
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end
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end
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# Validate the existing constraint. This can potentially take a very
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# long time to complete, but fortunately does not lock the source table
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# while running.
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# Disable this check by passing `validate: false` to the method call
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# The check will be enforced for new data (inserts) coming in,
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# but validating existing data is delayed.
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#
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# Note this is a no-op in case the constraint is VALID already
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if validate
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disable_statement_timeout do
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execute("ALTER TABLE #{source} VALIDATE CONSTRAINT #{options[:name]};")
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end
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end
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end
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# rubocop:enable Gitlab/RailsLogger
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def validate_foreign_key(source, column, name: nil)
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fk_name = name || concurrent_foreign_key_name(source, column)
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unless foreign_key_exists?(source, name: fk_name)
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raise missing_schema_object_message(source, "foreign key", fk_name)
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end
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disable_statement_timeout do
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execute("ALTER TABLE #{source} VALIDATE CONSTRAINT #{fk_name};")
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end
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end
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def foreign_key_exists?(source, target = nil, **options)
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foreign_keys(source).any? do |foreign_key|
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tables_match?(target.to_s, foreign_key.to_table.to_s) &&
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options_match?(foreign_key.options, options)
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end
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end
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# Returns the name for a concurrent foreign key.
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#
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# PostgreSQL constraint names have a limit of 63 bytes. The logic used
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# here is based on Rails' foreign_key_name() method, which unfortunately
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# is private so we can't rely on it directly.
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#
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# prefix:
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# - The default prefix is `fk_` for backward compatibility with the existing
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# concurrent foreign key helpers.
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# - For standard rails foreign keys the prefix is `fk_rails_`
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#
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def concurrent_foreign_key_name(table, column, prefix: 'fk_')
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identifier = "#{table}_#{column}_fk"
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hashed_identifier = Digest::SHA256.hexdigest(identifier).first(10)
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"#{prefix}#{hashed_identifier}"
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end
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# Long-running migrations may take more than the timeout allowed by
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# the database. Disable the session's statement timeout to ensure
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# migrations don't get killed prematurely.
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#
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# There are two possible ways to disable the statement timeout:
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#
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# - Per transaction (this is the preferred and default mode)
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# - Per connection (requires a cleanup after the execution)
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#
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# When using a per connection disable statement, code must be inside
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# a block so we can automatically execute `RESET ALL` after block finishes
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# otherwise the statement will still be disabled until connection is dropped
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# or `RESET ALL` is executed
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def disable_statement_timeout
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if block_given?
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if statement_timeout_disabled?
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# Don't do anything if the statement_timeout is already disabled
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# Allows for nested calls of disable_statement_timeout without
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# resetting the timeout too early (before the outer call ends)
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yield
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else
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begin
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execute('SET statement_timeout TO 0')
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yield
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ensure
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execute('RESET ALL')
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end
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end
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else
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unless transaction_open?
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raise <<~ERROR
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Cannot call disable_statement_timeout() without a transaction open or outside of a transaction block.
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If you don't want to use a transaction wrap your code in a block call:
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disable_statement_timeout { # code that requires disabled statement here }
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This will make sure statement_timeout is disabled before and reset after the block execution is finished.
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ERROR
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end
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execute('SET LOCAL statement_timeout TO 0')
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end
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end
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# Executes the block with a retry mechanism that alters the +lock_timeout+ and +sleep_time+ between attempts.
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# The timings can be controlled via the +timing_configuration+ parameter.
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# If the lock was not acquired within the retry period, a last attempt is made without using +lock_timeout+.
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#
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# ==== Examples
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# # Invoking without parameters
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# with_lock_retries do
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# drop_table :my_table
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# end
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#
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# # Invoking with custom +timing_configuration+
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# t = [
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# [1.second, 1.second],
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# [2.seconds, 2.seconds]
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# ]
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#
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# with_lock_retries(timing_configuration: t) do
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# drop_table :my_table # this will be retried twice
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# end
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#
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# # Disabling the retries using an environment variable
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# > export DISABLE_LOCK_RETRIES=true
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#
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# with_lock_retries do
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# drop_table :my_table # one invocation, it will not retry at all
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# end
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#
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# ==== Parameters
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# * +timing_configuration+ - [[ActiveSupport::Duration, ActiveSupport::Duration], ...] lock timeout for the block, sleep time before the next iteration, defaults to `Gitlab::Database::WithLockRetries::DEFAULT_TIMING_CONFIGURATION`
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# * +logger+ - [Gitlab::JsonLogger]
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# * +env+ - [Hash] custom environment hash, see the example with `DISABLE_LOCK_RETRIES`
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def with_lock_retries(**args, &block)
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merged_args = {
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klass: self.class,
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logger: Gitlab::BackgroundMigration::Logger
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}.merge(args)
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Gitlab::Database::WithLockRetries.new(merged_args).run(&block)
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end
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def true_value
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Database.true_value
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end
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def false_value
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Database.false_value
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end
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# Updates the value of a column in batches.
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#
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# This method updates the table in batches of 5% of the total row count.
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# A `batch_size` option can also be passed to set this to a fixed number.
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# This method will continue updating rows until no rows remain.
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#
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# When given a block this method will yield two values to the block:
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#
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# 1. An instance of `Arel::Table` for the table that is being updated.
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# 2. The query to run as an Arel object.
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#
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# By supplying a block one can add extra conditions to the queries being
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# executed. Note that the same block is used for _all_ queries.
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#
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# Example:
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#
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# update_column_in_batches(:projects, :foo, 10) do |table, query|
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# query.where(table[:some_column].eq('hello'))
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# end
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#
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# This would result in this method updating only rows where
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# `projects.some_column` equals "hello".
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#
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# table - The name of the table.
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# column - The name of the column to update.
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# value - The value for the column.
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#
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# The `value` argument is typically a literal. To perform a computed
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# update, an Arel literal can be used instead:
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#
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# update_value = Arel.sql('bar * baz')
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#
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# update_column_in_batches(:projects, :foo, update_value) do |table, query|
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# query.where(table[:some_column].eq('hello'))
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# end
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#
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# Rubocop's Metrics/AbcSize metric is disabled for this method as Rubocop
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# determines this method to be too complex while there's no way to make it
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# less "complex" without introducing extra methods (which actually will
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# make things _more_ complex).
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#
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# `batch_column_name` option is for tables without primary key, in this
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# case another unique integer column can be used. Example: :user_id
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#
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# rubocop: disable Metrics/AbcSize
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def update_column_in_batches(table, column, value, batch_size: nil, batch_column_name: :id)
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if transaction_open?
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raise 'update_column_in_batches can not be run inside a transaction, ' \
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'you can disable transactions by calling disable_ddl_transaction! ' \
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'in the body of your migration class'
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end
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table = Arel::Table.new(table)
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count_arel = table.project(Arel.star.count.as('count'))
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count_arel = yield table, count_arel if block_given?
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total = exec_query(count_arel.to_sql).to_a.first['count'].to_i
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return if total == 0
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if batch_size.nil?
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# Update in batches of 5% until we run out of any rows to update.
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batch_size = ((total / 100.0) * 5.0).ceil
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max_size = 1000
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# The upper limit is 1000 to ensure we don't lock too many rows. For
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# example, for "merge_requests" even 1% of the table is around 35 000
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# rows for GitLab.com.
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batch_size = max_size if batch_size > max_size
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end
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start_arel = table.project(table[batch_column_name]).order(table[batch_column_name].asc).take(1)
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start_arel = yield table, start_arel if block_given?
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start_id = exec_query(start_arel.to_sql).to_a.first[batch_column_name.to_s].to_i
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loop do
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stop_arel = table.project(table[batch_column_name])
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.where(table[batch_column_name].gteq(start_id))
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.order(table[batch_column_name].asc)
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.take(1)
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.skip(batch_size)
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stop_arel = yield table, stop_arel if block_given?
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stop_row = exec_query(stop_arel.to_sql).to_a.first
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update_arel = Arel::UpdateManager.new
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.table(table)
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.set([[table[column], value]])
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.where(table[batch_column_name].gteq(start_id))
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if stop_row
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stop_id = stop_row[batch_column_name.to_s].to_i
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start_id = stop_id
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update_arel = update_arel.where(table[batch_column_name].lt(stop_id))
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end
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update_arel = yield table, update_arel if block_given?
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execute(update_arel.to_sql)
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# There are no more rows left to update.
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break unless stop_row
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end
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end
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# Adds a column with a default value without locking an entire table.
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#
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# @deprecated With PostgreSQL 11, adding columns with a default does not lead to a table rewrite anymore.
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# As such, this method is not needed anymore and the default `add_column` helper should be used.
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# This helper is subject to be removed in a >13.0 release.
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def add_column_with_default(table, column, type, default:, limit: nil, allow_null: false)
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raise 'Deprecated: add_column_with_default does not support being passed blocks anymore' if block_given?
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add_column(table, column, type, default: default, limit: limit, null: allow_null)
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end
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# Renames a column without requiring downtime.
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#
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# Concurrent renames work by using database triggers to ensure both the
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# old and new column are in sync. However, this method will _not_ remove
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# the triggers or the old column automatically; this needs to be done
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# manually in a post-deployment migration. This can be done using the
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# method `cleanup_concurrent_column_rename`.
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#
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# table - The name of the database table containing the column.
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# old - The old column name.
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# new - The new column name.
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# type - The type of the new column. If no type is given the old column's
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# type is used.
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# batch_column_name - option is for tables without primary key, in this
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# case another unique integer column can be used. Example: :user_id
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def rename_column_concurrently(table, old, new, type: nil, type_cast_function: nil, batch_column_name: :id)
|
|
unless column_exists?(table, batch_column_name)
|
|
raise "Column #{batch_column_name} does not exist on #{table}"
|
|
end
|
|
|
|
if transaction_open?
|
|
raise 'rename_column_concurrently can not be run inside a transaction'
|
|
end
|
|
|
|
check_trigger_permissions!(table)
|
|
|
|
create_column_from(table, old, new, type: type, batch_column_name: batch_column_name, type_cast_function: type_cast_function)
|
|
|
|
install_rename_triggers(table, old, new)
|
|
end
|
|
|
|
# Reverses operations performed by rename_column_concurrently.
|
|
#
|
|
# This method takes care of removing previously installed triggers as well
|
|
# as removing the new column.
|
|
#
|
|
# table - The name of the database table.
|
|
# old - The name of the old column.
|
|
# new - The name of the new column.
|
|
def undo_rename_column_concurrently(table, old, new)
|
|
trigger_name = rename_trigger_name(table, old, new)
|
|
|
|
check_trigger_permissions!(table)
|
|
|
|
remove_rename_triggers_for_postgresql(table, trigger_name)
|
|
|
|
remove_column(table, new)
|
|
end
|
|
|
|
# Installs triggers in a table that keep a new column in sync with an old
|
|
# one.
|
|
#
|
|
# table - The name of the table to install the trigger in.
|
|
# old_column - The name of the old column.
|
|
# new_column - The name of the new column.
|
|
def install_rename_triggers(table, old_column, new_column)
|
|
trigger_name = rename_trigger_name(table, old_column, new_column)
|
|
quoted_table = quote_table_name(table)
|
|
quoted_old = quote_column_name(old_column)
|
|
quoted_new = quote_column_name(new_column)
|
|
|
|
install_rename_triggers_for_postgresql(
|
|
trigger_name,
|
|
quoted_table,
|
|
quoted_old,
|
|
quoted_new
|
|
)
|
|
end
|
|
|
|
# Changes the type of a column concurrently.
|
|
#
|
|
# table - The table containing the column.
|
|
# column - The name of the column to change.
|
|
# new_type - The new column type.
|
|
def change_column_type_concurrently(table, column, new_type, type_cast_function: nil)
|
|
temp_column = "#{column}_for_type_change"
|
|
|
|
rename_column_concurrently(table, column, temp_column, type: new_type, type_cast_function: type_cast_function)
|
|
end
|
|
|
|
# Performs cleanup of a concurrent type change.
|
|
#
|
|
# table - The table containing the column.
|
|
# column - The name of the column to change.
|
|
# new_type - The new column type.
|
|
def cleanup_concurrent_column_type_change(table, column)
|
|
temp_column = "#{column}_for_type_change"
|
|
|
|
transaction do
|
|
# This has to be performed in a transaction as otherwise we might have
|
|
# inconsistent data.
|
|
cleanup_concurrent_column_rename(table, column, temp_column)
|
|
rename_column(table, temp_column, column)
|
|
end
|
|
end
|
|
|
|
# Cleans up a concurrent column name.
|
|
#
|
|
# This method takes care of removing previously installed triggers as well
|
|
# as removing the old column.
|
|
#
|
|
# table - The name of the database table.
|
|
# old - The name of the old column.
|
|
# new - The name of the new column.
|
|
def cleanup_concurrent_column_rename(table, old, new)
|
|
trigger_name = rename_trigger_name(table, old, new)
|
|
|
|
check_trigger_permissions!(table)
|
|
|
|
remove_rename_triggers_for_postgresql(table, trigger_name)
|
|
|
|
remove_column(table, old)
|
|
end
|
|
|
|
# Reverses the operations performed by cleanup_concurrent_column_rename.
|
|
#
|
|
# This method adds back the old_column removed
|
|
# by cleanup_concurrent_column_rename.
|
|
# It also adds back the (old_column > new_column) trigger that is removed
|
|
# by cleanup_concurrent_column_rename.
|
|
#
|
|
# table - The name of the database table containing the column.
|
|
# old - The old column name.
|
|
# new - The new column name.
|
|
# type - The type of the old column. If no type is given the new column's
|
|
# type is used.
|
|
# batch_column_name - option is for tables without primary key, in this
|
|
# case another unique integer column can be used. Example: :user_id
|
|
def undo_cleanup_concurrent_column_rename(table, old, new, type: nil, batch_column_name: :id)
|
|
unless column_exists?(table, batch_column_name)
|
|
raise "Column #{batch_column_name} does not exist on #{table}"
|
|
end
|
|
|
|
if transaction_open?
|
|
raise 'undo_cleanup_concurrent_column_rename can not be run inside a transaction'
|
|
end
|
|
|
|
check_trigger_permissions!(table)
|
|
|
|
create_column_from(table, new, old, type: type, batch_column_name: batch_column_name)
|
|
|
|
install_rename_triggers(table, old, new)
|
|
end
|
|
|
|
# Changes the column type of a table using a background migration.
|
|
#
|
|
# Because this method uses a background migration it's more suitable for
|
|
# large tables. For small tables it's better to use
|
|
# `change_column_type_concurrently` since it can complete its work in a
|
|
# much shorter amount of time and doesn't rely on Sidekiq.
|
|
#
|
|
# Example usage:
|
|
#
|
|
# class Issue < ActiveRecord::Base
|
|
# self.table_name = 'issues'
|
|
#
|
|
# include EachBatch
|
|
#
|
|
# def self.to_migrate
|
|
# where('closed_at IS NOT NULL')
|
|
# end
|
|
# end
|
|
#
|
|
# change_column_type_using_background_migration(
|
|
# Issue.to_migrate,
|
|
# :closed_at,
|
|
# :datetime_with_timezone
|
|
# )
|
|
#
|
|
# Reverting a migration like this is done exactly the same way, just with
|
|
# a different type to migrate to (e.g. `:datetime` in the above example).
|
|
#
|
|
# relation - An ActiveRecord relation to use for scheduling jobs and
|
|
# figuring out what table we're modifying. This relation _must_
|
|
# have the EachBatch module included.
|
|
#
|
|
# column - The name of the column for which the type will be changed.
|
|
#
|
|
# new_type - The new type of the column.
|
|
#
|
|
# batch_size - The number of rows to schedule in a single background
|
|
# migration.
|
|
#
|
|
# interval - The time interval between every background migration.
|
|
def change_column_type_using_background_migration(
|
|
relation,
|
|
column,
|
|
new_type,
|
|
batch_size: 10_000,
|
|
interval: 10.minutes
|
|
)
|
|
|
|
unless relation.model < EachBatch
|
|
raise TypeError, 'The relation must include the EachBatch module'
|
|
end
|
|
|
|
temp_column = "#{column}_for_type_change"
|
|
table = relation.table_name
|
|
max_index = 0
|
|
|
|
add_column(table, temp_column, new_type)
|
|
install_rename_triggers(table, column, temp_column)
|
|
|
|
# Schedule the jobs that will copy the data from the old column to the
|
|
# new one. Rows with NULL values in our source column are skipped since
|
|
# the target column is already NULL at this point.
|
|
relation.where.not(column => nil).each_batch(of: batch_size) do |batch, index|
|
|
start_id, end_id = batch.pluck('MIN(id), MAX(id)').first
|
|
max_index = index
|
|
|
|
migrate_in(
|
|
index * interval,
|
|
'CopyColumn',
|
|
[table, column, temp_column, start_id, end_id]
|
|
)
|
|
end
|
|
|
|
# Schedule the renaming of the column to happen (initially) 1 hour after
|
|
# the last batch finished.
|
|
migrate_in(
|
|
(max_index * interval) + 1.hour,
|
|
'CleanupConcurrentTypeChange',
|
|
[table, column, temp_column]
|
|
)
|
|
|
|
if perform_background_migration_inline?
|
|
# To ensure the schema is up to date immediately we perform the
|
|
# migration inline in dev / test environments.
|
|
Gitlab::BackgroundMigration.steal('CopyColumn')
|
|
Gitlab::BackgroundMigration.steal('CleanupConcurrentTypeChange')
|
|
end
|
|
end
|
|
|
|
# Renames a column using a background migration.
|
|
#
|
|
# Because this method uses a background migration it's more suitable for
|
|
# large tables. For small tables it's better to use
|
|
# `rename_column_concurrently` since it can complete its work in a much
|
|
# shorter amount of time and doesn't rely on Sidekiq.
|
|
#
|
|
# Example usage:
|
|
#
|
|
# rename_column_using_background_migration(
|
|
# :users,
|
|
# :feed_token,
|
|
# :rss_token
|
|
# )
|
|
#
|
|
# table - The name of the database table containing the column.
|
|
#
|
|
# old - The old column name.
|
|
#
|
|
# new - The new column name.
|
|
#
|
|
# type - The type of the new column. If no type is given the old column's
|
|
# type is used.
|
|
#
|
|
# batch_size - The number of rows to schedule in a single background
|
|
# migration.
|
|
#
|
|
# interval - The time interval between every background migration.
|
|
def rename_column_using_background_migration(
|
|
table,
|
|
old_column,
|
|
new_column,
|
|
type: nil,
|
|
batch_size: 10_000,
|
|
interval: 10.minutes
|
|
)
|
|
|
|
check_trigger_permissions!(table)
|
|
|
|
old_col = column_for(table, old_column)
|
|
new_type = type || old_col.type
|
|
max_index = 0
|
|
|
|
add_column(table, new_column, new_type,
|
|
limit: old_col.limit,
|
|
precision: old_col.precision,
|
|
scale: old_col.scale)
|
|
|
|
# We set the default value _after_ adding the column so we don't end up
|
|
# updating any existing data with the default value. This isn't
|
|
# necessary since we copy over old values further down.
|
|
change_column_default(table, new_column, old_col.default) if old_col.default
|
|
|
|
install_rename_triggers(table, old_column, new_column)
|
|
|
|
model = Class.new(ActiveRecord::Base) do
|
|
self.table_name = table
|
|
|
|
include ::EachBatch
|
|
end
|
|
|
|
# Schedule the jobs that will copy the data from the old column to the
|
|
# new one. Rows with NULL values in our source column are skipped since
|
|
# the target column is already NULL at this point.
|
|
model.where.not(old_column => nil).each_batch(of: batch_size) do |batch, index|
|
|
start_id, end_id = batch.pluck('MIN(id), MAX(id)').first
|
|
max_index = index
|
|
|
|
migrate_in(
|
|
index * interval,
|
|
'CopyColumn',
|
|
[table, old_column, new_column, start_id, end_id]
|
|
)
|
|
end
|
|
|
|
# Schedule the renaming of the column to happen (initially) 1 hour after
|
|
# the last batch finished.
|
|
migrate_in(
|
|
(max_index * interval) + 1.hour,
|
|
'CleanupConcurrentRename',
|
|
[table, old_column, new_column]
|
|
)
|
|
|
|
if perform_background_migration_inline?
|
|
# To ensure the schema is up to date immediately we perform the
|
|
# migration inline in dev / test environments.
|
|
Gitlab::BackgroundMigration.steal('CopyColumn')
|
|
Gitlab::BackgroundMigration.steal('CleanupConcurrentRename')
|
|
end
|
|
end
|
|
|
|
# Performs a concurrent column rename when using PostgreSQL.
|
|
def install_rename_triggers_for_postgresql(trigger, table, old, new)
|
|
execute <<-EOF.strip_heredoc
|
|
CREATE OR REPLACE FUNCTION #{trigger}()
|
|
RETURNS trigger AS
|
|
$BODY$
|
|
BEGIN
|
|
NEW.#{new} := NEW.#{old};
|
|
RETURN NEW;
|
|
END;
|
|
$BODY$
|
|
LANGUAGE 'plpgsql'
|
|
VOLATILE
|
|
EOF
|
|
|
|
execute <<-EOF.strip_heredoc
|
|
DROP TRIGGER IF EXISTS #{trigger}
|
|
ON #{table}
|
|
EOF
|
|
|
|
execute <<-EOF.strip_heredoc
|
|
CREATE TRIGGER #{trigger}
|
|
BEFORE INSERT OR UPDATE
|
|
ON #{table}
|
|
FOR EACH ROW
|
|
EXECUTE FUNCTION #{trigger}()
|
|
EOF
|
|
end
|
|
|
|
# Removes the triggers used for renaming a PostgreSQL column concurrently.
|
|
def remove_rename_triggers_for_postgresql(table, trigger)
|
|
execute("DROP TRIGGER IF EXISTS #{trigger} ON #{table}")
|
|
execute("DROP FUNCTION IF EXISTS #{trigger}()")
|
|
end
|
|
|
|
# Returns the (base) name to use for triggers when renaming columns.
|
|
def rename_trigger_name(table, old, new)
|
|
'trigger_' + Digest::SHA256.hexdigest("#{table}_#{old}_#{new}").first(12)
|
|
end
|
|
|
|
# Returns an Array containing the indexes for the given column
|
|
def indexes_for(table, column)
|
|
column = column.to_s
|
|
|
|
indexes(table).select { |index| index.columns.include?(column) }
|
|
end
|
|
|
|
# Returns an Array containing the foreign keys for the given column.
|
|
def foreign_keys_for(table, column)
|
|
column = column.to_s
|
|
|
|
foreign_keys(table).select { |fk| fk.column == column }
|
|
end
|
|
|
|
# Copies all indexes for the old column to a new column.
|
|
#
|
|
# table - The table containing the columns and indexes.
|
|
# old - The old column.
|
|
# new - The new column.
|
|
def copy_indexes(table, old, new)
|
|
old = old.to_s
|
|
new = new.to_s
|
|
|
|
indexes_for(table, old).each do |index|
|
|
new_columns = index.columns.map do |column|
|
|
column == old ? new : column
|
|
end
|
|
|
|
# This is necessary as we can't properly rename indexes such as
|
|
# "ci_taggings_idx".
|
|
unless index.name.include?(old)
|
|
raise "The index #{index.name} can not be copied as it does not "\
|
|
"mention the old column. You have to rename this index manually first."
|
|
end
|
|
|
|
name = index.name.gsub(old, new)
|
|
|
|
options = {
|
|
unique: index.unique,
|
|
name: name,
|
|
length: index.lengths,
|
|
order: index.orders
|
|
}
|
|
|
|
options[:using] = index.using if index.using
|
|
options[:where] = index.where if index.where
|
|
|
|
unless index.opclasses.blank?
|
|
opclasses = index.opclasses.dup
|
|
|
|
# Copy the operator classes for the old column (if any) to the new
|
|
# column.
|
|
opclasses[new] = opclasses.delete(old) if opclasses[old]
|
|
|
|
options[:opclasses] = opclasses
|
|
end
|
|
|
|
add_concurrent_index(table, new_columns, options)
|
|
end
|
|
end
|
|
|
|
# Copies all foreign keys for the old column to the new column.
|
|
#
|
|
# table - The table containing the columns and indexes.
|
|
# old - The old column.
|
|
# new - The new column.
|
|
def copy_foreign_keys(table, old, new)
|
|
foreign_keys_for(table, old).each do |fk|
|
|
add_concurrent_foreign_key(fk.from_table,
|
|
fk.to_table,
|
|
column: new,
|
|
on_delete: fk.on_delete)
|
|
end
|
|
end
|
|
|
|
# Returns the column for the given table and column name.
|
|
def column_for(table, name)
|
|
name = name.to_s
|
|
|
|
column = columns(table).find { |column| column.name == name }
|
|
raise(missing_schema_object_message(table, "column", name)) if column.nil?
|
|
|
|
column
|
|
end
|
|
|
|
# This will replace the first occurrence of a string in a column with
|
|
# the replacement using `regexp_replace`
|
|
def replace_sql(column, pattern, replacement)
|
|
quoted_pattern = Arel::Nodes::Quoted.new(pattern.to_s)
|
|
quoted_replacement = Arel::Nodes::Quoted.new(replacement.to_s)
|
|
|
|
replace = Arel::Nodes::NamedFunction.new(
|
|
"regexp_replace", [column, quoted_pattern, quoted_replacement]
|
|
)
|
|
|
|
Arel::Nodes::SqlLiteral.new(replace.to_sql)
|
|
end
|
|
|
|
def remove_foreign_key_if_exists(*args)
|
|
if foreign_key_exists?(*args)
|
|
remove_foreign_key(*args)
|
|
end
|
|
end
|
|
|
|
def remove_foreign_key_without_error(*args)
|
|
remove_foreign_key(*args)
|
|
rescue ArgumentError
|
|
end
|
|
|
|
def sidekiq_queue_migrate(queue_from, to:)
|
|
while sidekiq_queue_length(queue_from) > 0
|
|
Sidekiq.redis do |conn|
|
|
conn.rpoplpush "queue:#{queue_from}", "queue:#{to}"
|
|
end
|
|
end
|
|
end
|
|
|
|
def sidekiq_queue_length(queue_name)
|
|
Sidekiq.redis do |conn|
|
|
conn.llen("queue:#{queue_name}")
|
|
end
|
|
end
|
|
|
|
def check_trigger_permissions!(table)
|
|
unless Grant.create_and_execute_trigger?(table)
|
|
dbname = Database.database_name
|
|
user = Database.username
|
|
|
|
raise <<-EOF
|
|
Your database user is not allowed to create, drop, or execute triggers on the
|
|
table #{table}.
|
|
|
|
If you are using PostgreSQL you can solve this by logging in to the GitLab
|
|
database (#{dbname}) using a super user and running:
|
|
|
|
ALTER #{user} WITH SUPERUSER
|
|
|
|
This query will grant the user super user permissions, ensuring you don't run
|
|
into similar problems in the future (e.g. when new tables are created).
|
|
EOF
|
|
end
|
|
end
|
|
|
|
# Fetches indexes on a column by name for postgres.
|
|
#
|
|
# This will include indexes using an expression on the column, for example:
|
|
# `CREATE INDEX CONCURRENTLY index_name ON table (LOWER(column));`
|
|
#
|
|
# We can remove this when upgrading to Rails 5 with an updated `index_exists?`:
|
|
# - https://github.com/rails/rails/commit/edc2b7718725016e988089b5fb6d6fb9d6e16882
|
|
#
|
|
# Or this can be removed when we no longer support postgres < 9.5, so we
|
|
# can use `CREATE INDEX IF NOT EXISTS`.
|
|
def index_exists_by_name?(table, index)
|
|
# We can't fall back to the normal `index_exists?` method because that
|
|
# does not find indexes without passing a column name.
|
|
if indexes(table).map(&:name).include?(index.to_s)
|
|
true
|
|
else
|
|
postgres_exists_by_name?(table, index)
|
|
end
|
|
end
|
|
|
|
def postgres_exists_by_name?(table, name)
|
|
index_sql = <<~SQL
|
|
SELECT COUNT(*)
|
|
FROM pg_index
|
|
JOIN pg_class i ON (indexrelid=i.oid)
|
|
JOIN pg_class t ON (indrelid=t.oid)
|
|
WHERE i.relname = '#{name}' AND t.relname = '#{table}'
|
|
SQL
|
|
|
|
connection.select_value(index_sql).to_i > 0
|
|
end
|
|
|
|
def create_or_update_plan_limit(limit_name, plan_name, limit_value)
|
|
limit_name_quoted = quote_column_name(limit_name)
|
|
plan_name_quoted = quote(plan_name)
|
|
limit_value_quoted = quote(limit_value)
|
|
|
|
execute <<~SQL
|
|
INSERT INTO plan_limits (plan_id, #{limit_name_quoted})
|
|
SELECT id, #{limit_value_quoted} FROM plans WHERE name = #{plan_name_quoted} LIMIT 1
|
|
ON CONFLICT (plan_id) DO UPDATE SET #{limit_name_quoted} = EXCLUDED.#{limit_name_quoted};
|
|
SQL
|
|
end
|
|
|
|
# Note this should only be used with very small tables
|
|
def backfill_iids(table)
|
|
sql = <<-END
|
|
UPDATE #{table}
|
|
SET iid = #{table}_with_calculated_iid.iid_num
|
|
FROM (
|
|
SELECT id, ROW_NUMBER() OVER (PARTITION BY project_id ORDER BY id ASC) AS iid_num FROM #{table}
|
|
) AS #{table}_with_calculated_iid
|
|
WHERE #{table}.id = #{table}_with_calculated_iid.id
|
|
END
|
|
|
|
execute(sql)
|
|
end
|
|
|
|
# Returns the name for a check constraint
|
|
#
|
|
# type:
|
|
# - Any value, as long as it is unique
|
|
# - Constraint names are unique per table in Postgres, and, additionally,
|
|
# we can have multiple check constraints over a column
|
|
# So we use the (table, column, type) triplet as a unique name
|
|
# - e.g. we use 'max_length' when adding checks for text limits
|
|
# or 'not_null' when adding a NOT NULL constraint
|
|
#
|
|
def check_constraint_name(table, column, type)
|
|
identifier = "#{table}_#{column}_check_#{type}"
|
|
# Check concurrent_foreign_key_name() for info on why we use a hash
|
|
hashed_identifier = Digest::SHA256.hexdigest(identifier).first(10)
|
|
|
|
"check_#{hashed_identifier}"
|
|
end
|
|
|
|
def check_constraint_exists?(table, constraint_name)
|
|
# Constraint names are unique per table in Postgres, not per schema
|
|
# Two tables can have constraints with the same name, so we filter by
|
|
# the table name in addition to using the constraint_name
|
|
check_sql = <<~SQL
|
|
SELECT COUNT(*)
|
|
FROM pg_constraint
|
|
JOIN pg_class ON pg_constraint.conrelid = pg_class.oid
|
|
WHERE pg_constraint.contype = 'c'
|
|
AND pg_constraint.conname = '#{constraint_name}'
|
|
AND pg_class.relname = '#{table}'
|
|
SQL
|
|
|
|
connection.select_value(check_sql).positive?
|
|
end
|
|
|
|
# Adds a check constraint to a table
|
|
#
|
|
# This method is the generic helper for adding any check constraint
|
|
# More specialized helpers may use it (e.g. add_text_limit or add_not_null)
|
|
#
|
|
# This method only requires minimal locking:
|
|
# - The constraint is added using NOT VALID
|
|
# This allows us to add the check constraint without validating it
|
|
# - The check will be enforced for new data (inserts) coming in
|
|
# - If `validate: true` the constraint is also validated
|
|
# Otherwise, validate_check_constraint() can be used at a later stage
|
|
# - Check comments on add_concurrent_foreign_key for more info
|
|
#
|
|
# table - The table the constraint will be added to
|
|
# check - The check clause to add
|
|
# e.g. 'char_length(name) <= 5' or 'store IS NOT NULL'
|
|
# constraint_name - The name of the check constraint (otherwise auto-generated)
|
|
# Should be unique per table (not per column)
|
|
# validate - Whether to validate the constraint in this call
|
|
#
|
|
# rubocop:disable Gitlab/RailsLogger
|
|
def add_check_constraint(table, check, constraint_name, validate: true)
|
|
validate_check_constraint_name!(constraint_name)
|
|
|
|
# Transactions would result in ALTER TABLE locks being held for the
|
|
# duration of the transaction, defeating the purpose of this method.
|
|
if transaction_open?
|
|
raise 'add_check_constraint can not be run inside a transaction'
|
|
end
|
|
|
|
if check_constraint_exists?(table, constraint_name)
|
|
warning_message = <<~MESSAGE
|
|
Check constraint was not created because it exists already
|
|
(this may be due to an aborted migration or similar)
|
|
table: #{table}, check: #{check}, constraint name: #{constraint_name}
|
|
MESSAGE
|
|
|
|
Rails.logger.warn warning_message
|
|
else
|
|
# Only add the constraint without validating it
|
|
# Even though it is fast, ADD CONSTRAINT requires an EXCLUSIVE lock
|
|
# Use with_lock_retries to make sure that this operation
|
|
# will not timeout on tables accessed by many processes
|
|
with_lock_retries do
|
|
execute <<-EOF.strip_heredoc
|
|
ALTER TABLE #{table}
|
|
ADD CONSTRAINT #{constraint_name}
|
|
CHECK ( #{check} )
|
|
NOT VALID;
|
|
EOF
|
|
end
|
|
end
|
|
|
|
if validate
|
|
validate_check_constraint(table, constraint_name)
|
|
end
|
|
end
|
|
|
|
def validate_check_constraint(table, constraint_name)
|
|
validate_check_constraint_name!(constraint_name)
|
|
|
|
unless check_constraint_exists?(table, constraint_name)
|
|
raise missing_schema_object_message(table, "check constraint", constraint_name)
|
|
end
|
|
|
|
disable_statement_timeout do
|
|
# VALIDATE CONSTRAINT only requires a SHARE UPDATE EXCLUSIVE LOCK
|
|
# It only conflicts with other validations and creating indexes
|
|
execute("ALTER TABLE #{table} VALIDATE CONSTRAINT #{constraint_name};")
|
|
end
|
|
end
|
|
|
|
def remove_check_constraint(table, constraint_name)
|
|
validate_check_constraint_name!(constraint_name)
|
|
|
|
# DROP CONSTRAINT requires an EXCLUSIVE lock
|
|
# Use with_lock_retries to make sure that this will not timeout
|
|
with_lock_retries do
|
|
execute <<-EOF.strip_heredoc
|
|
ALTER TABLE #{table}
|
|
DROP CONSTRAINT IF EXISTS #{constraint_name}
|
|
EOF
|
|
end
|
|
end
|
|
|
|
# Migration Helpers for adding limit to text columns
|
|
def add_text_limit(table, column, limit, constraint_name: nil, validate: true)
|
|
add_check_constraint(
|
|
table,
|
|
"char_length(#{column}) <= #{limit}",
|
|
text_limit_name(table, column, name: constraint_name),
|
|
validate: validate
|
|
)
|
|
end
|
|
|
|
def validate_text_limit(table, column, constraint_name: nil)
|
|
validate_check_constraint(table, text_limit_name(table, column, name: constraint_name))
|
|
end
|
|
|
|
def remove_text_limit(table, column, constraint_name: nil)
|
|
remove_check_constraint(table, text_limit_name(table, column, name: constraint_name))
|
|
end
|
|
|
|
def check_text_limit_exists?(table, column, constraint_name: nil)
|
|
check_constraint_exists?(table, text_limit_name(table, column, name: constraint_name))
|
|
end
|
|
|
|
# Migration Helpers for managing not null constraints
|
|
def add_not_null_constraint(table, column, constraint_name: nil, validate: true)
|
|
if column_is_nullable?(table, column)
|
|
add_check_constraint(
|
|
table,
|
|
"#{column} IS NOT NULL",
|
|
not_null_constraint_name(table, column, name: constraint_name),
|
|
validate: validate
|
|
)
|
|
else
|
|
warning_message = <<~MESSAGE
|
|
NOT NULL check constraint was not created:
|
|
column #{table}.#{column} is already defined as `NOT NULL`
|
|
MESSAGE
|
|
|
|
Rails.logger.warn warning_message
|
|
end
|
|
end
|
|
|
|
def validate_not_null_constraint(table, column, constraint_name: nil)
|
|
validate_check_constraint(
|
|
table,
|
|
not_null_constraint_name(table, column, name: constraint_name)
|
|
)
|
|
end
|
|
|
|
def remove_not_null_constraint(table, column, constraint_name: nil)
|
|
remove_check_constraint(
|
|
table,
|
|
not_null_constraint_name(table, column, name: constraint_name)
|
|
)
|
|
end
|
|
|
|
def check_not_null_constraint_exists?(table, column, constraint_name: nil)
|
|
check_constraint_exists?(
|
|
table,
|
|
not_null_constraint_name(table, column, name: constraint_name)
|
|
)
|
|
end
|
|
|
|
private
|
|
|
|
def validate_check_constraint_name!(constraint_name)
|
|
if constraint_name.to_s.length > MAX_IDENTIFIER_NAME_LENGTH
|
|
raise "The maximum allowed constraint name is #{MAX_IDENTIFIER_NAME_LENGTH} characters"
|
|
end
|
|
end
|
|
|
|
def statement_timeout_disabled?
|
|
# This is a string of the form "100ms" or "0" when disabled
|
|
connection.select_value('SHOW statement_timeout') == "0"
|
|
end
|
|
|
|
def column_is_nullable?(table, column)
|
|
# Check if table.column has not been defined with NOT NULL
|
|
check_sql = <<~SQL
|
|
SELECT c.is_nullable
|
|
FROM information_schema.columns c
|
|
WHERE c.table_name = '#{table}'
|
|
AND c.column_name = '#{column}'
|
|
SQL
|
|
|
|
connection.select_value(check_sql) == 'YES'
|
|
end
|
|
|
|
def text_limit_name(table, column, name: nil)
|
|
name.presence || check_constraint_name(table, column, 'max_length')
|
|
end
|
|
|
|
def not_null_constraint_name(table, column, name: nil)
|
|
name.presence || check_constraint_name(table, column, 'not_null')
|
|
end
|
|
|
|
def missing_schema_object_message(table, type, name)
|
|
<<~MESSAGE
|
|
Could not find #{type} "#{name}" on table "#{table}" which was referenced during the migration.
|
|
This issue could be caused by the database schema straying from the expected state.
|
|
|
|
To resolve this issue, please verify:
|
|
1. all previous migrations have completed
|
|
2. the database objects used in this migration match the Rails definition in schema.rb or structure.sql
|
|
|
|
MESSAGE
|
|
end
|
|
|
|
def tables_match?(target_table, foreign_key_table)
|
|
target_table.blank? || foreign_key_table == target_table
|
|
end
|
|
|
|
def options_match?(foreign_key_options, options)
|
|
options.all? { |k, v| foreign_key_options[k].to_s == v.to_s }
|
|
end
|
|
|
|
def on_delete_statement(on_delete)
|
|
return '' if on_delete.blank?
|
|
return 'ON DELETE SET NULL' if on_delete == :nullify
|
|
|
|
"ON DELETE #{on_delete.upcase}"
|
|
end
|
|
|
|
def create_column_from(table, old, new, type: nil, batch_column_name: :id, type_cast_function: nil)
|
|
old_col = column_for(table, old)
|
|
new_type = type || old_col.type
|
|
|
|
add_column(table, new, new_type,
|
|
limit: old_col.limit,
|
|
precision: old_col.precision,
|
|
scale: old_col.scale)
|
|
|
|
# We set the default value _after_ adding the column so we don't end up
|
|
# updating any existing data with the default value. This isn't
|
|
# necessary since we copy over old values further down.
|
|
change_column_default(table, new, old_col.default) unless old_col.default.nil?
|
|
|
|
old_value = Arel::Table.new(table)[old]
|
|
|
|
if type_cast_function.present?
|
|
old_value = Arel::Nodes::NamedFunction.new(type_cast_function, [old_value])
|
|
end
|
|
|
|
update_column_in_batches(table, new, old_value, batch_column_name: batch_column_name)
|
|
|
|
add_not_null_constraint(table, new) unless old_col.null
|
|
|
|
copy_indexes(table, old, new)
|
|
copy_foreign_keys(table, old, new)
|
|
end
|
|
|
|
def validate_timestamp_column_name!(column_name)
|
|
return if PERMITTED_TIMESTAMP_COLUMNS.member?(column_name)
|
|
|
|
raise <<~MESSAGE
|
|
Illegal timestamp column name! Got #{column_name}.
|
|
Must be one of: #{PERMITTED_TIMESTAMP_COLUMNS.to_a}
|
|
MESSAGE
|
|
end
|
|
|
|
def validate_not_in_transaction!(method_name, modifier = nil)
|
|
return unless transaction_open?
|
|
|
|
raise <<~ERROR
|
|
#{["`#{method_name}`", modifier].compact.join(' ')} cannot be run inside a transaction.
|
|
|
|
You can disable transactions by calling `disable_ddl_transaction!` in the body of
|
|
your migration class
|
|
ERROR
|
|
end
|
|
end
|
|
end
|
|
end
|