70 lines
1.8 KiB
Ruby
70 lines
1.8 KiB
Ruby
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require_dependency 'migration/base_dropper'
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module Migration
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class Migration::TableDropper < BaseDropper
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def self.delayed_drop(old_name:, new_name:, after_migration:, delay: nil, on_drop: nil)
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validate_table_name(old_name)
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validate_table_name(new_name)
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TableDropper.new(old_name, new_name, after_migration, delay, on_drop).delayed_drop
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end
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def self.read_only_table(table_name)
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create_readonly_function(table_name)
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ActiveRecord::Base.exec_sql <<~SQL
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CREATE TRIGGER #{readonly_trigger_name(table_name)}
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BEFORE INSERT OR UPDATE OR DELETE OR TRUNCATE
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ON #{table_name}
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FOR EACH STATEMENT
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EXECUTE PROCEDURE #{readonly_function_name(table_name)};
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SQL
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end
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private
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def initialize(old_name, new_name, after_migration, delay, on_drop)
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super(after_migration, delay, on_drop)
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@old_name = old_name
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@new_name = new_name
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end
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def droppable?
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builder = SqlBuilder.new(<<~SQL)
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SELECT 1
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FROM INFORMATION_SCHEMA.TABLES
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/*where*/
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LIMIT 1
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SQL
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builder.where("table_schema = 'public'")
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.where(previous_migration_done)
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.where(new_table_exists)
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.exec(old_name: @old_name,
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new_name: @new_name,
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delay: "#{@delay} seconds",
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after_migration: @after_migration).to_a.length > 0
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end
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def new_table_exists
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<<~SQL
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EXISTS(
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SELECT 1
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FROM INFORMATION_SCHEMA.TABLES
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WHERE table_schema = 'public' AND
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table_name = :new_name
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)
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SQL
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end
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def execute_drop!
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ActiveRecord::Base.exec_sql("DROP TABLE IF EXISTS #{@old_name}")
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ActiveRecord::Base.exec_sql <<~SQL
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DROP FUNCTION IF EXISTS #{BaseDropper.readonly_function_name(@old_name)} CASCADE;
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SQL
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end
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end
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end
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