python 操所sqlite3

__author__ = 'Administrator'
import sqlite3,random
src="qwertyuiopasdfghjklzxcvbnm"

def get_str(x,y):
    str_sum=random.randint(x,y)
    astr=""
    for i in range(str_sum):
        astr+=random.choice(src)
    return astr

def output():
    cur.execute("select * from mytab")
    for sid,name,ps in cur:
        print(sid," ",name," ",ps)
def output_all():
    cur.execute("select * from mytab")
    for sid,name,pas in cur.fetchall():
        print(sid," ",name," ",pas)
def get_data_list(n):
    res=[]
    for i in range(n):
        res.append((get_str(2,4),get_str(8,12)))
    return  res
if __name__=="__main__":
    print("建立连接")
    con=sqlite3.connect(":memory:")
    print("建立游标")
    cur=con.cursor()
    print("创建一张表mytable")
    cur.execute("create table mytab(id integer primary key autoincrement not null,name text ,password text)")
    print("插入一条记录")
    cur.execute("insert into mytab(name,password) values(?,?)",(get_str(2,4),get_str(8,12),))
    output()
    print("批量插入数据库")
    cur.executemany("insert into mytab(name,password) values(?,?)",get_data_list(3))
    print("显示所有记录")
    output_all()
    print("更新一条记录")
    cur.execute("update mytab set name=? where id=?",("aaa",1))
    print("显示所有记录")
    output()
    print("删除一条记录")
    cur.execute("delete from mytab where id=?",(3,))#删除一条记录
    print("显示所有记录")
    output()
    cur.close()
    con.close()