35 lines
1.6 KiB
Ruby
35 lines
1.6 KiB
Ruby
require 'migrate'
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class OrderRelationMembers < ActiveRecord::Migration
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def self.up
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# add sequence column. rails won't let us define an ordering here,
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# as defaults must be constant.
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add_column(:relation_members, :sequence_id, :integer,
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:default => 0, :null => false)
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# update the sequence column with default (partial) ordering by
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# element ID. the sequence ID is a smaller int type, so we can't
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# just copy the member_id.
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execute("update relation_members set sequence_id = mod(member_id, 16384)")
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# need to update the primary key to include the sequence number,
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# otherwise the primary key will barf when we have repeated members.
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# mysql barfs on this anyway, so we need a single command. this may
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# not work in postgres... needs testing.
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alter_primary_key("relation_members", [:id, :version, :member_type, :member_id, :member_role, :sequence_id])
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# do the same for the current tables
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add_column(:current_relation_members, :sequence_id, :integer,
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:default => 0, :null => false)
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execute("update current_relation_members set sequence_id = mod(member_id, 16384)")
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alter_primary_key("current_relation_members", [:id, :member_type, :member_id, :member_role, :sequence_id])
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end
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def self.down
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alter_primary_key("current_relation_members", [:id, :member_type, :member_id, :member_role])
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remove_column :relation_members, :sequence_id
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alter_primary_key("relation_members", [:id, :version, :member_type, :member_id, :member_role])
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remove_column :current_relation_members, :sequence_id
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end
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end
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