Python：//PySqlite3/Python对于Sqlite3数据库操作

PySqlite3.py

#coding:utf-8
"""
Python-Sqlite3数据库操作
自定义数据类型存储
"""
import sqlite3
try:
	import cPickle as pickle
except :
	import pickle

db_filename='todo.db'

def adapter_func(obj):
	"""
	Convert from in-memory to storage representation
	封装并存储数据
	"""
	print 'adapter_func(%s)n' % obj
	return pickle.dumps(obj)

def converter_func(data):
	"""
	Convert from storage to in-memory representation
	拆封并提取数据
	"""
	print 'converter_func(%s)' % data
	return pickle.loads(data)

class MyObj(object):
	"""
	自定义数据类型
	"""
	def __init__(self,arg):
		self.arg=arg
	def __str__(self):
		return 'MyObj(%s)' % self.arg

#Register the function for manipulating the type
sqlite3.register_adapter(MyObj,adapter_func)
sqlite3.register_converter("MyObj",converter_func)

#Create some object to save
to_save = [ (MyObj('this is a value to save'),),
	(MyObj(42),),]

with sqlite3.connect(db_filename, detect_types=sqlite3.PARSE_DECLTYPES) as conn:
	#Create a table with column of type 'MyObj'
	#执行SQL语句
	conn.execute("""
	create table if not exists obj(id integer primary key autoincrement not null,
	data MyObj)
	""")
	#创建游标对象
	cursor=conn.cursor()
	#Insert the objects into the database
	#向obj表中插入数据
	cursor.executemany("insert into obj (data) values (?)", to_save)
	#Query the database for the object just saved
	#从'obj'表中查询'id'键和'data'值
	cursor.execute("select * from obj where id = 1")
	print('========this is the id-data inquery========\n{}'.format(cursor.fetchone()))
	#更新数据
	#cursor.execute("update obj set data=MyObj(80) where id = 4")
	#删除数据
	cursor.execute("delete from obj where id = 5")
	#从结果取出所有记录
	cursor.execute("select id,data from obj")
	for obj_id,obj in cursor.fetchall():
		print 'Retrieved:',obj_id,obj,type(obj)