python 实现mysql 查询

来源：互联网发布：java python 数据分析编辑：程序博客网时间：2024/04/30 13:20

要想使Python可以操作MySQL数据库，首先需要安装MySQL-python包，在CentOS上可以使用一下命令来安装

$ sudo yum install MySQL-python

啥都不说了，走两步吧，下面的程序创建了一个到mysql数据库的连接，然后执行了一个简单的查询，并打印查询结果

import MySQLdb  conn = MySQLdb.connect (host = "172.17.23.121", user = "fkong", passwd = "fkong", db = "fkong")  cursor = conn.cursor ()  cursor.execute ("SELECT VERSION()")  row = cursor.fetchone ()  print "MySQL server version:", row[0]  cursor.close ()  conn.close ()

下面看一个数据库建表和插入操作

import MySQLdb  conn = MySQLdb.connect (host = "172.17.23.121", user = "fkong", passwd = "fkong", db = "fkong")  cursor = conn.cursor ()  cursor.execute ("""     CREATE TABLE TEST     (         ID INT,         COL1 VARCHAR(40),         COL2 VARCHAR(40),         COL3 VARCHAR(40)     )     """)  cursor.execute ("""     INSERT INTO TEST (ID, COL1, COL2, COL3)     VALUES         (1, 'a', 'b', 'c'),         (2, 'aa', 'bb', 'cc'),         (3, 'aaa', 'bbb', 'ccc')     """)  conn.commit()  cursor.close ()  conn.close ()

下面再来看看查询，查询通常有两种方式：一种是使用cursor.fetchall（）获取所有查询结果，然后再一行一行的迭代；另一种每次通过cursor.fetchone()获取一条记录，直到获取的结果为空为止。看一下下面的例子：

import MySQLdb  conn = MySQLdb.connect (host = "172.17.23.121", user = "fkong", passwd = "fkong", db = "fkong")  cursor = conn.cursor ()  cursor.execute ("SELECT * FROM TEST")  rows = cursor.fetchall()  for row in rows:      print "%d, %s, %s, %s" % (row[0], row[1], row[2], row[3])  print "Number of rows returned: %d" % cursor.rowcount  cursor.execute ("SELECT * FROM TEST")  while (True):      row = cursor.fetchone()      if row == None:          break      print "%d, %s, %s, %s" % (row[0], row[1], row[2], row[3])  print "Number of rows returned: %d" % cursor.rowcount  cursor.close ()  conn.close ()

0 0