Module: AlsoMigrate::Migrator::InstanceMethods::AlsoMigrate

Defined in:
lib/also_migrate/migrator.rb

Class Method Summary collapse

Class Method Details

.connectionObject



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# File 'lib/also_migrate/migrator.rb', line 30

def connection
  ActiveRecord::Base.connection
end

.create_tables(config) ⇒ Object



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# File 'lib/also_migrate/migrator.rb', line 34

def create_tables(config)
  [ config[:destination] ].flatten.compact.each do |new_table|
    if !connection.table_exists?(new_table) && connection.table_exists?(config[:source])
      columns = connection.columns(config[:source]).collect(&:name)
      columns -= [ config[:subtract] ].flatten.compact.collect(&:to_s)
      columns.collect! { |col| connection.quote_column_name(col) }
      if config[:indexes]
        engine =
          if connection.class.to_s.include?('Mysql')
            'ENGINE=' + connection.select_one(<<-SQL)['Engine']
              SHOW TABLE STATUS
              WHERE Name = '#{config[:source]}'
            SQL
          end
        connection.execute(<<-SQL)
          CREATE TABLE #{new_table} #{engine}
          AS SELECT #{columns.join(',')}
          FROM #{config[:source]}
          WHERE false;
        SQL
        [ config[:indexes] ].flatten.compact.each do |column|
          connection.add_index(new_table, column)
        end
      else
        if connection.class.to_s.include?('SQLite')
          col_string = connection.columns(config[:source]).collect {|c|
            "#{c.name} #{c.sql_type}"
          }.join(', ')
          connection.execute(<<-SQL)
            CREATE TABLE #{new_table}
            (#{col_string})
          SQL
        else
          connection.execute(<<-SQL)
            CREATE TABLE #{new_table}
            LIKE #{config[:source]};
          SQL
        end
      end
    end
    if connection.table_exists?(new_table)
      if config[:add] || config[:subtract]
        columns = connection.columns(new_table).collect(&:name)
      end
      if config[:add]
        config[:add].each do |column|
          unless columns.include?(column[0])
            connection.add_column(*([ new_table ] + column))
          end
        end
      end
      if config[:subtract]
        [ config[:subtract] ].flatten.compact.each do |column|
          if columns.include?(column)
            connection.remove_column(new_table, column)
          end
        end
      end
    end
  end
end