Class: Mysql2psql::PostgresWriter

Inherits:
Writer
  • Object
show all
Defined in:
lib/mysql2psql/postgres_writer.rb

Direct Known Subclasses

PostgresDbWriter, PostgresFileWriter

Instance Method Summary collapse

Instance Method Details

#column_default(column) ⇒ Object 



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# File 'lib/mysql2psql/postgres_writer.rb', line 49

def column_default(column)
  if column[:auto_increment]
    "nextval('#{column[:table_name]}_#{column[:name]}_seq'::regclass)"
  elsif column[:default]
    case column[:type]
    when 'char'
      "'#{PGconn.escape(column[:default])}'::char"
    when 'varchar', /^enum/
      "'#{PGconn.escape(column[:default])}'::character varying"
    when 'integer', 'bigint', /tinyint|smallint/
      column[:default].to_i
    when 'real', /float/
      column[:default].to_f
    when 'decimal', 'double precision'
      column[:default]
    when 'boolean'
      case column[:default]
      when nil
        'NULL'
      when 0, '0', "b'0'"
        'false'
      else
        # Case for 1, '1', "b'1'" (for BIT(1) the data type), or anything non-nil and non-zero (for the TINYINT(1) type)
        'true'
      end
    when 'timestamp', 'datetime', 'date'
      case column[:default]
      when 'CURRENT_TIMESTAMP'
        'CURRENT_TIMESTAMP'
      when '0000-00-00'
        "'1970-01-01'"
      when '0000-00-00 00:00'
        "'1970-01-01 00:00'"
      when '0000-00-00 00:00:00'
        "'1970-01-01 00:00:00'"
      else
        "'#{PGconn.escape(column[:default])}'"
      end
    when 'time'
      "'#{PGconn.escape(column[:default])}'"
    else
      # TODO: column[:default] will never be nil here.
      #       Perhaps we should also issue a warning if this case is encountered.
      "#{column[:default] == nil ? 'NULL' : "'"+PGconn.escape(column[:default])+"'"}"
    end
  end
end

#column_description(column, options) ⇒ Object 



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# File 'lib/mysql2psql/postgres_writer.rb', line 8

def column_description(column, options)
  "#{PGconn.quote_ident(column[:name])} #{column_type_info(column, options)}"
end

#column_type(column, options = {}) ⇒ Object 



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# File 'lib/mysql2psql/postgres_writer.rb', line 12

def column_type(column, options={})
  if column[:auto_increment]
    'integer'
  else
    case column[:type]
    when 'char'
      "character(#{column[:length]})"
    when 'varchar'
      "character varying(#{column[:length]})"
    when /tinyint|smallint/
      'smallint'
    when 'real', /float/, 'double precision'
      'double precision'
    when 'decimal'
      # TODO: seven1m thinks "real" instead?
      "numeric(#{column[:length] || 10}, #{column[:decimals] || 5})"
    when 'datetime', 'timestamp'
      "timestamp with#{options[:use_timezones] ? '' : 'out'} time zone"
    when 'time'
      "time with#{options[:use_timezones] ? '' : 'out'} time zone"
    when 'tinyblob', 'mediumblob', 'longblob', 'blob', 'varbinary'
      'bytea'
    when 'tinytext', 'mediumtext', 'longtext', 'text'
      'text'
    when /^enum/
      enum = column[:type].gsub(/enum|\(|\)/, '')
      max_enum_size = enum.split(',').map{ |check| check.size() -2}.sort[-1]
      "character varying(#{max_enum_size}) check( #{column[:name]} in (#{enum}))"
    when 'integer', 'bigint', 'boolean', 'date'
      column[:type]
    else
      puts "Unknown #{column.inspect}"
      ''
    end
  end
end

#column_type_info(column, options) ⇒ Object 



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# File 'lib/mysql2psql/postgres_writer.rb', line 97

def column_type_info(column, options)
  type = column_type(column, options)
  if type
    not_null = !column[:null] || column[:auto_increment] ? ' NOT NULL' : ''
    default = column[:default] || column[:auto_increment] ? " DEFAULT #{column_default(column)}" : ''
    "#{type}#{default}#{not_null}"
  else
    ''
  end
end

#process_row(table, row) ⇒ Object 



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# File 'lib/mysql2psql/postgres_writer.rb', line 108

def process_row(table, row)
  table.columns.each_with_index do |column, index|
    if column[:type] == 'time'
      begin
        row[index] = "%02d:%02d:%02d" % [row[index].hour, row[index].minute, row[index].second]
      rescue
        # Don't fail on nil date/time.
      end
    elsif row[index].is_a?(Mysql::Time)
      row[index] = row[index].to_s.gsub('0000-00-00 00:00', '1970-01-01 00:00')
      row[index] = row[index].to_s.gsub('0000-00-00 00:00:00', '1970-01-01 00:00:00')
    elsif column[:type] == 'boolean'
      row[index] = (
        case row[index]
        when nil
          '\N' # See note below about null values.
        when 0, "\0"
          'f'
        else
          # Case for 1, "\1" (for the BIT(1) data type), or anything non-nil and non-zero (to handle the TINYINT(1) type)
          't'
        end
      )
    elsif row[index].is_a?(String)
      if column_type(column) == "bytea"
        row[index] = PGconn.escape_bytea(row[index])
      else
        if row[index] == '\N' || row[index] == '\.'
          row[index] = '\\' + row[index] # Escape our two PostgreSQL-text-mode-special strings.
        else
          # Awesome side-effect producing conditional. Don't do this at home.
          unless row[index].gsub!(/\0/, '').nil?
            puts "Removed null bytes from string since PostgreSQL TEXT types don't allow the storage of null bytes."
          end
          
          row[index] = row[index].dump
          row[index] = row[index].slice(1, row[index].size-2)
        end
      end
    elsif row[index].nil?
      # Note: '\N' not "\N" is correct here:
      #       The string containing the literal backslash followed by 'N'
      #       represents database NULL value in PostgreSQL's text mode.
      row[index] = '\N'
    end
  end
end

#sqlfor_reset_serial_sequence(table, serial_key, max_value) ⇒ Object 



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# File 'lib/mysql2psql/postgres_writer.rb', line 162

def sqlfor_reset_serial_sequence(table, serial_key, max_value)
  "SELECT pg_catalog.setval(pg_get_serial_sequence('#{table.name}', '#{serial_key}'), #{max_value}, true);"
end

#sqlfor_set_serial_sequence(table, serial_key_seq, max_value) ⇒ Object 



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# File 'lib/mysql2psql/postgres_writer.rb', line 159

def sqlfor_set_serial_sequence(table, serial_key_seq, max_value)
  "SELECT pg_catalog.setval('#{serial_key_seq}', #{max_value}, true);"
end

#truncate(table) ⇒ Object 



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# File 'lib/mysql2psql/postgres_writer.rb', line 156

def truncate(table)
end