慕课 python 操作数据库

test_connection

 1 import MySQLdb
 2 
 3 conn = MySQLdb.Connect(
 4     host = '127.0.0.1',
 5     port = 3306,
 6     user = '*****',
 7     passwd = '*****',
 8     db = 'czy',
 9     charset = 'utf8'
10     )
11 
12 cursor = conn.cursor()
13 
14 print conn
15 print cursor
16 
17 cursor.close()
18 conn.close()

结果：

<_mysql.connection open to '127.0.0.1' at 21f0980>
<MySQLdb.cursors.Cursor object at 0x0228BA30>

test_coursor：

 1 import MySQLdb
 2 
 3 conn = MySQLdb.Connect(
 4     host = '127.0.0.1',
 5     port = 3306,
 6     user = '****',
 7     passwd = '****',
 8     db = 'czy',
 9     charset = 'utf8'
10     )
11 
12 cursor = conn.cursor()
13 
14 sql = "select * from user"
15 cursor.execute(sql)
16 
17 print cursor.rowcount
18 
19 rs = cursor.fetchone()
20 print rs
21 
22 rs = cursor.fetchmany(3)
23 print rs
24 
25 rs = cursor.fetchall()
26 print rs
27 
28 cursor.close()
29 conn.close()

结果：

1 9
2 (1L, u'name1')
3 ((2L, u'name2'), (3L, u'name3'), (4L, u'name4'))
4 ((5L, u'name5'), (6L, u'name6'), (7L, u'name7'), (8L, u'name8'), (9L, u'name9'))

test_select:

 1 import MySQLdb
 2 
 3 conn = MySQLdb.Connect(
 4     host = '127.0.0.1',
 5     port = 3306,
 6     user = '**',
 7     passwd = '**',
 8     db = 'czy',
 9     charset = 'utf8'
10     )
11 
12 cursor = conn.cursor()
13 
14 sql = "select * from user"
15 cursor.execute(sql)
16 
17 rs = cursor.fetchall()
18 
19 for row in rs:
20     print "userid = %s,username = %s" % row
21 
22 cursor.close()
23 conn.close()

结果：

userid = 1,username = name1
userid = 2,username = name2
userid = 3,username = name3
userid = 4,username = name4
userid = 5,username = name5
userid = 6,username = name6
userid = 7,username = name7
userid = 8,username = name8
userid = 9,username = name9

test_iud:

 1 import MySQLdb
 2 
 3 conn = MySQLdb.Connect(
 4     host = '127.0.0.1',
 5     port = 3306,
 6     user = '',
 7     passwd = '',
 8     db = 'czy',
 9     charset = 'utf8'
10     )
11 
12 cursor = conn.cursor()
13 
14 sql_insert = "insert into user(userid,username) values(10,'name10')"
15 sql_update = "update user set username='name91' where userid=9"
16 sql_delete = "delete from user where userd<3"
17 
18 try:
19     cursor.execute(sql_insert)
20     print cursor.rowcount 
21 
22     cursor.execute(sql_update)
23     print cursor.rowcount 
24 
25     cursor.execute(sql_delete)
26     print cursor.rowcount 
27 
28     conn.commit()
29 except Exception, e:
30     print e
31     conn.rollback()
32 
33 
34 
35 cursor.close()
36 conn.close()

结果（没有影响数据库，因为第三条语句失败了）：

1
1
(1054, "Unknown column 'userd' in 'where clause'")

posted on 2016-06-05 08:59 njczy2010 阅读(224) 评论(0) 编辑收藏举报