Python中SQLite3的基本操作实例讲解

# -*- coding: utf-8 -*-

#!/usr/bin/env python

import sqlite3

def mykey(x):

  return x[3]

conn=sqlite3.connect("D:\\demo\\my_db.db")

sql = "CREATE TABLE IF NOT EXISTS mytb ( a char , b int , c real, d DATE)"

# a char , b int , c real 表示该表有三个字段，

# a 是字符串类型， b 是整数类型, c 是实数类型。

conn.execute( sql )

cs = conn.cursor()

#cs.execute("DELETE FROM mytb WHERE A='张三' ")

cs.execute("DELETE FROM mytb  ")

#删除所有记录

'''''

cs.execute( "INSERT INTO mytb ( a,b,c,d ) values('Zhang San',25, 120, '2014-03-04')" )

cs.execute( "INSERT INTO mytb ( a,b,c,d ) values( 'Wang Wu',24, 110, '2014-05-01')" )

cs.execute( "INSERT INTO mytb ( a,b,c,d ) values( 'Li Si',23, 130, '2014-04-06')" )

'''

#批量注入，batchdata是一个列表，列表里每一个元素都是一个元组

batchdata=[('Zhang San',25, 120, '2014-03-04'),

      ( 'Wang Wu',24, 110, '2014-05-01'),

      ( 'Li Si',23, 130, '2014-04-06')]

cs.executemany('INSERT INTO mytb values (?,?,?,?)',batchdata)

conn.commit() #将加入的记录保存到磁盘，非常重要！

cs.execute("SELECT name, sql FROM sqlite_master WHERE type='table'")

recs = cs.fetchall( )

print ( recs )

cs.execute( "SELECT * FROM mytb ")#打开数据表

recs = cs.fetchall()#取出所有记录

print ( "there is ", len(recs)," notes." )

print recs

recs.sort(key = mykey)

print recs

cs.close()

conn.close()

sql="DELETE FROM my_table WHERE number='" + my_num + "'"

cs.execute(sql)

sql="SELECT name FROM my_table WHERE number ='" + my_num + "'"

cs.execute(sql)

the_name=(cs.fetchall())[0][0].decode('utf-8')

sql="INSERT OR REPLACE INTO "+my_table+" values (?,?,?,?,?,?,?) "

#假设my_table有7项

batch=[(stock_num, unicode(stock_name, "gbk") )]

cs.executemany( "INSERT OR REPLACE INTO my_table values (?,?) ",batch)