torndb是facebook开源的一个基于MySQLdb二次封装的一个mysql模块,新封装的这个模块比较小,是一个只有2百多行代码的py文件。虽然代码短,功能确相较MySQLdb简便不少,并且该模块由于增加了reconnect方法和max_idel_time参数,解决了mysql的断连问题。该模块之前在 python torndb模块 篇中也提到过。这里就结合上一篇 python mysql 断连报错处理 问题,比较下使用原生MySQLdb模块和使用torndb模块的代码。

一、代码比较

1、使用MySQLdb模块的代码

 1import MySQLdb
 2def getTerm(db,tag):
 3        cursor = db.cursor()
 4        query = "SELECT term_id FROM wp_terms where name=%s "
 5        count = cursor.execute(query,tag)
 6        rows = cursor.fetchall()
 7        db.commit()
 8        #db.close()
 9        if count:
10                term_id = [int(rows[id][0]) for id in range(count)]
11                return term_id
12        else:return None
13def addTerm(db,tag):
14        cursor = db.cursor()
15        query = "INSERT into wp_terms (name,slug,term_group) values (%s,%s,0)"
16        data = (tag,tag)
17        cursor.execute(query,data)
18        db.commit()
19        term_id = cursor.lastrowid
20        sql = "INSERT into wp_term_taxonomy (term_id,taxonomy,description) values (%s,'post_tag',%s) "
21        value = (term_id,tag)
22        cursor.execute(sql,value)
23        db.commit()
24        db.close()
25        return int(term_id)
26def addCTag(db,data):
27        cursor = db.cursor()
28        query = '''INSERT INTO `wp_term_relationships` (
29           `object_id` ,
30           `term_taxonomy_id`
31           )
32           VALUES (
33           %s, %s) '''
34        cursor.executemany(query,data)
35        db.commit()
36        db.close()
37dbconn = MySQLdb.connect(host='localhost', user='root', passwd='123456', db='361way', port=3306, charset='utf8', init_command='set names utf8')
38tags = ['mysql','1111','aaaa','bbbb','ccccc','php','abc','python','java']
39tagids = []
40for tag in tags:
41        if termid:
42               try:
43                  dbconn.ping()
44               except:
45                  dbconn = MySQLdb.connect(host='localhost', user='root', passwd='123456', db='361way', port=3306, charset='utf8', init_command='set names utf8')
46                  print tag, 'tag id is ',termid
47               termid = getTerm(dbconn,tag)
48               tagids.extend(termid)
49        else:
50               try:
51                  dbconn.ping()
52               except:
53                  dbconn = MySQLdb.connect(host='localhost', user='root', passwd='123456', db='361way', port=3306, charset='utf8', init_command='set names utf8')
54               termid = addTerm(dbconn,tag)
55               print 'add tag',tag,'id is ' ,termid
56               tagids.append(termid)
57print 'tag id is ',tagids
58postid = '35'
59tagids = list(set(tagids))
60ctagdata = []
61for tagid in tagids:
62    ctagdata.append((postid,tagid))
63try:
64    dbconn.ping()
65except:
66    dbconn = MySQLdb.connect(host='localhost', user='root', passwd='123456', db='361way', port=3306, charset='utf8', init_command='set names utf8')
67    addCTag(dbconn,ctagdata)

2、使用torndb的代码

 1#!/usr/bin/python
 2#coding=utf-8
 3import torndb
 4def getTerm(db,tag):
 5        query = "SELECT term_id FROM wp_terms where name=%s "
 6        rows = db.query(query,tag)
 7        termid = []
 8        for row in rows:
 9            termid.extend(row.values())
10        return termid
11def addTerm(db,tag):
12        query = "INSERT into wp_terms (name,slug,term_group) values (%s,%s,0)"
13        term_id = db.execute_lastrowid(query,tag,tag)
14        sql = "INSERT into wp_term_taxonomy (term_id,taxonomy,description) values (%s,'post_tag',%s) "
15        db.execute(sql,term_id,tag)
16        return term_id
17def addCTag(db,data):
18        query = "INSERT INTO wp_term_relationships (object_id,term_taxonomy_id) VALUES (%s, %s) "
19        db.executemany(query,data)
20dbconn = torndb.Connection('localhost:3306','361way',user='root',password='123456')
21tags = ['mysql','1111','aaaa','bbbb','ccccc','php','abc','python','java']
22tagids = []
23for tag in tags:
24    termid = getTerm(dbconn,tag)
25    if termid:
26        print tag, 'tag id is ',termid
27        tagids.extend(termid)
28    else:
29        termid = addTerm(dbconn,tag)
30        print 'add tag',tag,'id is ' ,termid
31        tagids.append(termid)
32print 'All tags id is ',tagids
33postid = '35'
34tagids = list(set(tagids))
35ctagdata = []
36for tagid in tagids:
37    ctagdata.append((postid,tagid))
38addCTag(dbconn,ctagdata)

从两者的代码上来看,使用torndb模块和原生相比,发现可以省略如下两部分:

1、torndb模块不需要db.cursor进行处理,无不需要db.comment提交,torndb是自动提交的;
2、torndb不需要在每次调用时,进行db.ping()判断数据库socket连接是否断开,因为torndb增加了reconnect方法,支持自动重连。

二、torndb的方法

torndb提供的参数和方法有:

 1execute                      执行语句不需要返回值的操作
 2execute_lastrowid            执行后获得表id一般用于插入后获取返回值
 3executemany                  可以执行批量插入返回值为第一次请求的表id
 4executemany_rowcount         批量执行返回值为第一次请求的表id
 5get                          执行后获取一行数据返回dict
 6iter                         执行查询后返回迭代的字段和数据
 7query                        执行后获取多行数据返回是List
 8close                        关闭
 9max_idle_time                最大连接时间
10reconnect                    关闭后再连接

使用示例:

 1mysql> CREATE TABLE `ceshi` (`id` int(1) NULL AUTO_INCREMENT ,`num` int(1) NULL ,PRIMARY KEY (`id`));
 2>>> import torndb
 3>>> db = torndb.Connection("127.0.0.1","数据库名","用户名", "密码", 24*3600)   # 24*3600为超时时间
 4>>> get_id1 = db.execute_lastrowid("insert ceshi(num) values('1')")
 5>>> print get_id1
 61
 7>>> args1 = [('2'),('3'),('4')]
 8>>> get1 = db.executemany("insert ceshi(num) values(%s)", args1)
 9>>> print get1
102
11>>> rows = db.iter("select * from ceshi")
12>>> for i in rows:
13 print i

三、报错

在使用过程中可能遇到的错误:

1File "/home/361way/database.py", line 145, in execute_lastrowid
2    self._execute(cursor, query, parameters)
3  File "/home/361way/database.py", line 207, in _execute
4    return cursor.execute(query, parameters)
5  File "/usr/lib/pymodules/python2.7/MySQLdb/cursors.py", line 159, in execute
6    query = query % db.literal(args)
7TypeError: not enough arguments for format string

写上面的代码时,我刚开始还是试着使用MySQLdb模块的方式引用数据,结果发现报参数的错误 ,经查看代码发现 ,torndb在使用几个sql方法时较MySQLdb精简过了。具体各个方法的传参方法如下(注意参数个数):

 1close()
 2reconnect()
 3iter(query, *parameters, **kwparameters)
 4query(query, *parameters, **kwparameters)
 5get(query, *parameters, **kwparameters)
 6execute(query, *parameters, **kwparameters)
 7execute_lastrowid(query, *parameters, **kwparameters)
 8execute_rowcount(query, *parameters, **kwparameters)
 9executemany(query, parameters)
10executemany_lastrowid(query, parameters)
11executemany_rowcount(query, parameters)
12update(query, *parameters, **kwparameters)
13updatemany(query, parameters)
14insert(query, *parameters, **kwparameters)
15insertmany(query, parameters)