データの更新（update）

  Const UPDATE_VALUE_SQL As String = "update t_value set value = :value " & _
                  "where term = :term and company_id = :company_id and market_id = " & GET_MARKET_ID_SQL & " and datetime = :datetime " & _
                  " and category_id = " & GET_CATEGORY_ID_SQL & " and item_id = " & GET_ITEM_ID_SQL & " ;"

  Sub BeginTx()
    _tx = _conn.BeginTransaction()
    _createCom = New NpgsqlCommand(SET_VALUE_SQL, _conn, _tx)
    InitCreateUpdate(_createCom)
    _updateCom = New NpgsqlCommand(UPDATE_VALUE_SQL, _conn, _tx)
    InitCreateUpdate(_updateCom)
  End Sub

  Sub Update(ByVal sv As SeqValue)
    CreateUpdate(_updateCom, sv)
  End Sub

Dim dao As New SeqValueDAO
dao.BeginTx()
dao.Create(seqValue1)
dao.Create(seqValue2)
dao.Create(seqValue3)
dao.Update(seqValue4)
dao.Update(seqValue5)
dao.Update(seqValue6)
' ・・・
dao.CommitTx()