Python_sqlite3

 import sqlite3  #导入模块
 conn = sqlite3.connect('example.db')    #连接数据库
 c = conn.cursor()
 #创建表
 c.execute('''CREATE TABLE stocks(date text,trans text,symbol text,qty real,price real)''')
 #插入一条纪录
 c.execute("INSERT INTO stocks VALUES('2016-01-05','BUY','RHAT',100,35.14)")
 #提交当前事务，保存数据
 conn.commit()
 #关闭数据库连接
 conn.close()

 connSe = sqlite3.connect('example.db')
 c = connSe.cursor()
 for row in c.execute('SELECT * FROM stocks ORDER BY price'):
     print(row)

#调用自定义函数

 import sqlite3
 import hashlib

 #自定义函数
 def md5sum(t):
     return hashlib.md5(t).hexdigest()

 #在内存中创建临时数据库
 conn = sqlite3.connect(":memory:")
 #创建可在SQL语句中调用的函数
 conn.create_function("md5",1,md5sum)
 cur = conn.cursor()
 #在SQL语句中调用自定义函数
 cur.execute("select md5(?)",["中国北京".encode()])
 print(cur.fetchone()[0])

#占位符的使用

 import sqlite3

 conn = sqlite3.connect(":memory:")
 cur = conn.cursor()
 cur.execute("CREATE TABLE people(name_last,age)")
 who='Dong'
 age=''
 #使用问号作为占位符
 cur.execute('insert into people values(?,?)',(who,age))
 #使用命名变量作为占位符
 cur.execute('select *from people where name_last=:who and age=:age',{'who':who,'age':age})
 print(cur.fetchone())

#迭代器生成数据

 import sqlite3

 #自定义迭代器，按顺序生成小写字母
 class IterChars:
     def __init__(self):
         self.count = ord('a')
     def __iter__(self):
         return self
     def __next__(self):
         if self.count > ord('z'):
             raise StopIteration
         self.count +=1
         return (chr(self.count-1))
 conn = sqlite3.connect(":memory:")
 cur = conn.cursor()
 cur.execute("create table characcters(c)")
 #创建迭代器对象
 theIter = IterChars()
 #插入记录，每次插入一个英文小写字母
 cur.executemany('insert into characcters(c)values(?)',theIter)
 #读取并显示所有记录
 cur.execute('select c from characcters')
 print(cur.fetchall())

#迭代器生成更简洁的方式

 #下面的代码则使用了更为简洁的生成器来产生参数：
 import sqlite3
 import string

 #包含yield语句的函数可以用来创建生成器对象
 def char_generator():
     for c in string.ascii_lowercase:
         yield (c,)

 conn = sqlite3.connect(":memory:")
 cur = conn.cursor()
 cur.execute("create table characters(c)")
 #使用生成器对象得到参数序列
 cur.executemany("insert into characters(c)values(?)",char_generator())
 cur.execute('select c from characters')
 print(cur.fetchall())

 import sqlite3
 person=[('Hugo','Boss'),('Calvin','Klein')]
 conn=sqlite3.connect(":memory:")
 #创建表
 conn.execute('create table person(firstname,lastname)')
 #插入数据
 conn.executemany('insert into person(firstname,lastname) values (?,?)',person)
 #显示数据
 for row in conn.execute('select firstname,lastname from person'):
     print(row)
 print('I just deleted',conn.execute('delete from person').rowcount,'rows')

 '''用来读取数据
 fetchone()
 fetchmany(size=cursor,arraysize)
 fetchall()
 '''
 import sqlite3

 conn = sqlite3.connect('addressBook.db')
 conn.execute('create table addressList(name,sex,phon,QQ,address)')
 cur =  conn.cursor()    #创建游标
 cur.execute("insert into addressList(name,sex,phon,QQ,address)values('王小丫','女','13111110010','66735','北京市')")
 cur.execute("insert into addressList(name,sex,phon,QQ,address)values('李莉莉','女','11231110010','66755','天津市')")
 cur.execute("insert into addressList(name,sex,phon,QQ,address)values('李发莉','女','11235410010','66723','开封市')")
 conn.commit()   #提交事务，把数据写入数据库

 cur.execute('select *from addressList')
 li=cur.fetchall()   #返回所有查询结果
 for line in li:
     for item in line:
         print(item,end=' ')
     print()

 conn.close()

 '''Row对象'''
 #假设数据以下面的方式创建并插入数据:
 import sqlite3
 conn = sqlite3.connect('test.db')
 c=conn.cursor()
 c.execute("create table stocks(date text,trans text,symbol text,qty real,price real)")
 c.execute("insert into stocks values('2016-01-05','BUY','RHAT',100,35.14)")
 conn.commit()

 #使用下面的方式来读取其中的数据：
 conn.row_factory = sqlite3.Row
 c=conn.cursor()
 c.execute('select * from stocks')
 r=c.fetchone()
 print(type(r))
 print(tuple(r))
 print(r[2])
 print(r.keys())
 print(r['qty'])
 for field in r:
     print(field)
 conn.close()