O/Rmapper from minnanoPython

simplemapper.py

@classmethod
def createtable(cls,ignore_error=False):
	"""
	定義に基づいてテーブルを作る
	"""
	sql="""CREATE TABLE %s (
					id INTEGER PRIMARY KEY, %s);"""
	columns=','.join(["%s %s" % (k,v) for k,v in cls.rows])
	sql=sql % (cls.__name__,columns)
	cur=cls.getconnection().cucrsor()
	try:
		cur.execute(sql)
	except Exception, e:
		if not ignore_error:
			raise e
	cur.close()
	cls.getconnection().commit()

@classmethod
def insert(cls,**kws):
	"""
	データを追加し、IDを返す
	"""
	sql="""INSERT INTO %s(%s) VALUES(%s)"""
	rownames=','.join([v[0] for v in cls.rows])
	holders=','.join(['?' for v in cls.rows])
	sql=sql % (cls.__name__,rownames,holders)
	values=[kws[v[0]] for v in cls.rows]
	cur=cls.getconnection().cursor()
	cur.execute(sql,values)
	cur.execute("SELECT max(id) FROM %s" % cls.__name__)
	newid=cur.fetchone()[0]
	cls.getconnection().comit()
	cur.close()
	return newid

class BaseMapper(object):
	"""
	シンプルな機能を持つO/Rマッパーベースクラス
	"""
	rows=()
	
	connection=sqlite3.connect(':memory:')
	
	@classmethod
	def setconnection(cls,con):
		cls.connection=con
	@classmethod
	def getconnection(cls):
		return cls.connection
	def __init__(self,**kws):
		"""
		クラスを初期化する
		idを奇数に渡された場合既存データをSELECTして渡す
		その他のキーワードが引数に渡された場合は、データをDBにINSERTする
		"""
		if 'id' in kws.keys():
			rownames=[v[0] for v in self.__class__.rows]
			rownamestr=','.join(rownames)
			cn=self.__class__.__name__
			sql="""SELECT %s FROM %s WHERE id=?""" % (rownamestr,cn)
			cur=self.getconnection().cursor()
			cur.execute(sqlm(kws['id'],))
			for rowname,v in zip(rownames,cur.fetchone()):
				setattr(self,rowname,v)
			self.id=kws['id']
			cur.close()
		elif kws:
			self.id=self.insert(**kws)
			rownames=[v[0] for v in self.__class__.rows]
			for k in kws.keys():
				if k in rownames:
					setattr(self,k,kws[k])
	def update(self):
		"""
		データを更新する
		"""
		sql="""UPDATE %s SET %s WHERE id=?"""
		rownames=[v[0] for v in self.__class__.rows]
		holders=','.join(['%s=?'% v for v in rownames])
		sql=sql % (self.__class__.__name__,holders)
		values=[getattr(self,n) for n in rownames]
		values.append(self.id)
		cur=self.getconnection().cursor()
		cur.execute(sql,values)
		self.getconnection().commit()
		cur.close()
	
	where_conditions={
		'_gt':'>','_lt':'<',
		'_gte':'>=','_lte':'<=',
		'like':'LIKE'}
	
	@classmethod
	def select(cls,**kws):
		"""
		テーブルからデータをSELECTする
		"""
		order=''
		if "oder_by" in kws.keys():
			order="ORDER BY"+kws['order_by']
			del kws['order_by']
		where=[]
		values=[]
		for key in kws.keys():
			ct='='
			kwkeys=cls.where_conditions.keys()
			for ckey in kwkeys:
				if key.endwith(ckey):
					ct=cls.where_conditions[ckey]
					kws[key.replace(ckey,'')]=kws[key]
					del kws[key]
					key=key.replace(ckey,'')
					break
			where.append(' '.join((key,ct,'? ')))
			values.append(kws[key])
		wherestr="AND ".join(where)
		sql="SELECT id FROM "+cls.__name__
		if wherestr:
			sql+=" WHERE "+wherestr
		sql+=order
		cur=cls.getconnection().cursor()
		cur.execute(sql,values)
		for item in cur.fetchall():
			ins=cls(id=item[0])
			yield ins
		cur.close()
		
		def __repr__(self):
			"""
			オブジェクトの文字列表記を定義
			"""
			rep=str(self.__class__.__name__)+':'
			rownames=[v[0] for v in self.__class__.rows]
			rep+=', '.join(["%s=%s"% (x, repr(getattr(self,x))) for x in rownames])
			return "<%s>"% rep