Python和MySql:Unicode和编码

Question

我正在解析json数据，并试图将一些json数据存储到Mysql数据库中。我目前正在跟踪unicode错误。我的问题是我该怎么处理。

• 我应该从数据库的角度来处理它，如果是的话，我应该如何修改表来处理它？
• 我应该从python端处理它吗？

这是我的桌子结构

CREATE TABLE yahoo_questions (
   question_id varchar(40) NOT NULL, 
   question_subj varbinary(255), 
   question_content varbinary(255),
   question_userId varchar(40) NOT NULL,
   question_timestamp varchar(40),
   category_id varbinary(20) NOT NULL,
   category_name varchar(40) NOT NULL,
   choosen_answer varbinary(255),
   choosen_userId varchar(40),
   choosen_usernick varchar(40),
   choosen_ans_timestamp varchar(40),
   UNIQUE (question_id)
);

通过python代码插入时出错：

Traceback (most recent call last):
  File "YahooQueryData.py", line 78, in <module>
    +"VALUES (%s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s)", (row[2], row[5], row[6], quserId, questionTime, categoryId, categoryName, qChosenAnswer, choosenUserId, choosenNickName, choosenTimeStamp))
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/MySQLdb/cursors.py", line 159, in execute
    query = query % db.literal(args)
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/MySQLdb/connections.py", line 264, in literal
    return self.escape(o, self.encoders)
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/MySQLdb/connections.py", line 202, in unicode_literal
    return db.literal(u.encode(unicode_literal.charset))
UnicodeEncodeError: 'latin-1' codec can't encode characters in position 204-230: ordinal not in range(256)

Python代码段：

    #pushing user id to the url to get full json stack
    urlobject = urllib.urlopen(base_url.format(row[2]))
    qnadatajson = urlobject.read()
    data = json.loads(qnadatajson)
cur.execute("INSERT INTO yahoo_questions (question_id, question_subj, question_content, question_userId, question_timestamp,"
            +"category_id, category_name, choosen_answer, choosen_userId, choosen_usernick, choosen_ans_timestamp)"
            +"VALUES (%s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s)", (row[2], row[5], row[6], quserId, questionTime, categoryId, categoryName, qChosenAnswer, choosenUserId, choosenNickName, choosenTimeStamp))

json结构

questions: [
{
Id: "20111201185322AA5HTDc",
Subject: "what are the new pokemon call?",
Content: "I used to know them I stop at dialga and palkia version and I heard there's new ones what's it call
",
Date: "2011-12-01 18:53:22",
Timestamp: "1322794402",

在运行查询之前，我还对mysql SET character_set_client = utf8执行了以下操作

mysql变量看起来是这样的：

mysql> SHOW variables LIKE '%character_set%';
+--------------------------+--------------------------------------------------------+
| Variable_name            | Value                                                  |
+--------------------------+--------------------------------------------------------+
| character_set_client     | utf8                                                   |
| character_set_connection | utf8                                                   |
| character_set_database   | latin1                                                 |
| character_set_filesystem | binary                                                 |
| character_set_results    | utf8                                                   |
| character_set_server     | latin1                                                 |
| character_set_system     | utf8                                                   |
| character_sets_dir       | /usr/local/mysql-5.5.10-osx10.6-x86_64/share/charsets/ |
+--------------------------+--------------------------------------------------------+
8 rows in set (0.00 sec)

Answer 1

首先，确保在建立MySQL连接时分配charset和use_unicode参数：

conn = mysql.connect(host='127.0.0.1',
                     user='user',
                     passwd='passwd',
                     db='db',
                     charset='utf8',
                     use_unicode=True)

其次，在实际查询数据库时使用prepared statements。下面是包含unicode字符的字符串的插入查询示例。

cursor.execute('INSERT INTO mytable VALUES (null, %s)',                  
               ('Some string that contains unicode: ' + unichr(300),))

Answer 2

我认为MYSQLdb python库不知道它应该编码为utf8，而是编码为默认的python系统定义的字符集latin1。

当您connect()到数据库时，请传递charset='utf8'参数。这也应该使手册SET NAMES或SET character_set_client不必要。