07 August 2012

python操作mysql需要用到MySQLdb这个库。

  1. 下载MySQLdb,点击这里下载
  2. 使用

     import MySQLdb  
     try:  
     	con = MySQLdb.connect(host='192.168.1.100', user='myuser', passwd='123456', port='3306', db='mydb',charset='utf8')  
     	c = con.cursor()  
     	c.execute('select * from user');  
     	rows=c.fetchall() #一次读取所有数据,返回的数据结构[(?,?,...),(?,?,..),..]  
     	for row in rows:  
         	for column in row:  
             	print column  
     except Exception,e:  
     	print e  
     finally:  
     	c.close()  
     	con.close()  
    
     import MySQLdb  
     try:  
     	con = MySQLdb.connect(host='192.168.1.100', user='myuser', passwd='123456', port='3306', db='mydb',charset='utf8')  
     	c = con.cursor()  
     	#使用占位符传递参数,参数是一个tuple  
     	c.execute('select * from user where user=%s',('root'));  
     	rows=c.fetchall() #一次读取所有数据,返回的数据结构[(?,?,...),(?,?,..),..]  
     	for row in rows:  
         	for column in row:  
             	print column  
     except Exception,e:  
     	print e  
     finally:  
         c.close()  
     	con.close()  
    
     import MySQLdb  
     try:  
     	con = MySQLdb.connect(host='192.168.1.100', user='myuser', passwd='123456', port='3306', db='mydb',charset='utf8')  
     	c = con.cursor()  
     	#使用占位符传递参数,参数是一个tuple  
     	c.execute('update user set host=%s where user=%s',('root','192.168.1.200'));  
     	con.commit() #更新操作记得提交事物,否则更改不会生效  
     except Exception,e:  
     	print e  
     finally:  
     	c.close()  
     	con.close()  
    
     import MySQLdb  
     try:  
     	con = MySQLdb.connect(host='192.168.1.100', user='myuser', passwd='123456', port='3306', db='mydb',charset='utf8')  
     	c = con.cursor()  
     	vs=[]  
     	vs.append(('root','192.168.1.100'))  
     	vs.append(('db','192.168.1.101'))  
     	vs.append(('pdb','192.168.1.101'))  
     	#使用占位符传递参数,参数是一个list tuple  
     	c.executemany('insert into user(user,host)values(%s,%s)',vs);  
     	con.commit() #更新操作记得提交事物,否则更改不会生效  
     except Exception,e:  
     	print e  
     finally:  
     	c.close()  
     	con.close()  
    
  3. 注意事项

咋看一下其中占位符和字符串格式化差不多,天真的以为数字用%d,浮点数用%f,字符串用%s,那你可以就要悲剧了

事实上这里的占位符只能是%s



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