PLC/Storage/AlchemyObject.py

   1 from datetime import datetime
   2
   3 from sqlalchemy.ext.declarative import declarative_base
   4 from sqlalchemy import Table, Column, MetaData, join, ForeignKey
   5 from sqlalchemy import Column, Integer, String
   6 from sqlalchemy import Table, Column, MetaData, join, ForeignKey
   7 from sqlalchemy.orm import relationship, backref
   8 from sqlalchemy.orm import column_property
   9 from sqlalchemy.orm import mapper, object_mapper
  10 from sqlalchemy.orm import validates
  11 from sqlalchemy import ForeignKey
  12
  13 from PLC.Storage.Alchemy import Base, engine, dbsession
  14 from PLC.Storage.Record import Record
  15 from PLC.Timestamp import Timestamp
  16 from PLC.Logger import logger
  17
  18 class AlchemyObj(Record):
  19
  20     def __init__(self, api=None, fields = {}, object=None):
  21         Record.__init__(self, dict=fields, object=object)
  22         self.api=api
  23
  24     def __iter__(self):
  25         self._i = iter(object_mapper(self).columns)
  26         return self
  27
  28     def next(self):
  29         n = self._i.next().name
  30         return n, getattr(self, n)
  31
  32     def get_table(self):
  33         metadata = MetaData(engine)
  34         table = Table(self.tablename, metadata)
  35         for field in self.fields:
  36             param = self.fields[field]
  37             # skip params joined from other tables
  38             if param.joined:
  39                 continue
  40             type = String
  41             if param.type == int:
  42                 type = Integer
  43             elif param.type == datetime:
  44                 type = DateTime
  45             column = Column(field, type,
  46                             nullable = param.nullok,
  47                             indexed = param.indexed,
  48                             primary_key=param.primary_key)
  49             table.append_column(column)
  50         if not table.exists():
  51             table.create()
  52         return table
  53
  54     def create(self):
  55         table = self.get_table()
  56         table.create()
  57
  58     def insert(self, values):
  59         table = self.get_table()
  60         result = dbsession.execute(table.insert().values(values))
  61         dbsession.commit()
  62         return result
  63
  64     def updatedb(self, filter, values):
  65         class Cls(object): pass
  66         table = self.get_table()
  67         clsmapper = mapper(Cls, table)
  68         result = dbsession.query(clsmapper).filter_by(**filter).update(values)
  69         dbsession.commit()
  70         return result
  71
  72     def delete(self, filter={}):
  73         class Cls(object): pass
  74         table = self.get_table()
  75         clsmapper = mapper(Cls, table)
  76         result = dbsession.query(clsmapper).filter_by(**filter).delete()
  77         dbsession.commit()
  78         return result
  79
  80     def select(self, filter={}):
  81         class Cls(object): pass
  82         table = self.get_table()
  83         clsmapper = mapper(Cls, table)
  84         return dbsession.query(clsmapper).filter_by(**filter)