Django에서 유니 코드 문자열을 저장할 때 MySQL "잘못된 문자열 값"오류

Django에서 유니 코드 문자열을 저장할 때 MySQL "잘못된 문자열 값"오류

---

first_name, last_name을 Django의 auth_user 모델에 저장하려고 할 때 이상한 오류 메시지가 나타납니다.

실패한 예

user = User.object.create_user(username, email, password)
user.first_name = u'Rytis'
user.last_name = u'Slatkevičius'
user.save()
>>> Incorrect string value: '\xC4\x8Dius' for column 'last_name' at row 104

user.first_name = u'Валерий'
user.last_name = u'Богданов'
user.save()
>>> Incorrect string value: '\xD0\x92\xD0\xB0\xD0\xBB...' for column 'first_name' at row 104

user.first_name = u'Krzysztof'
user.last_name = u'Szukiełojć'
user.save()
>>> Incorrect string value: '\xC5\x82oj\xC4\x87' for column 'last_name' at row 104

성공한 예

user.first_name = u'Marcin'
user.last_name = u'Król'
user.save()
>>> SUCCEED

MySQL 설정

mysql> show variables like 'char%';
+--------------------------+----------------------------+
| Variable_name            | Value                      |
+--------------------------+----------------------------+
| character_set_client     | utf8                       | 
| character_set_connection | utf8                       | 
| character_set_database   | utf8                       | 
| character_set_filesystem | binary                     | 
| character_set_results    | utf8                       | 
| character_set_server     | utf8                       | 
| character_set_system     | utf8                       | 
| character_sets_dir       | /usr/share/mysql/charsets/ | 
+--------------------------+----------------------------+
8 rows in set (0.00 sec)

테이블 문자셋과 콜 레이션

auth_user 테이블에는 utf8_general_ci 데이터 정렬이 포함 된 utf-8 문자 세트가 있습니다.

UPDATE 명령의 결과

UPDATE 명령을 사용하여 위의 값을 auth_user 테이블로 업데이트 할 때 오류가 발생하지 않았습니다.

mysql> update auth_user set last_name='Slatkevičiusa' where id=1;
Query OK, 1 row affected, 1 warning (0.00 sec)
Rows matched: 1  Changed: 1  Warnings: 0

mysql> select last_name from auth_user where id=100;
+---------------+
| last_name     |
+---------------+
| Slatkevi?iusa | 
+---------------+
1 row in set (0.00 sec)

PostgreSQL

장고에서 데이터베이스 백엔드를 전환하면 위에 나열된 실패한 값을 PostgreSQL 테이블로 업데이트 할 수 있습니다. 이상하다.

mysql> SHOW CHARACTER SET;
+----------+-----------------------------+---------------------+--------+
| Charset  | Description                 | Default collation   | Maxlen |
+----------+-----------------------------+---------------------+--------+
...
| utf8     | UTF-8 Unicode               | utf8_general_ci     |      3 | 
...

그러나 http://www.postgresql.org/docs/8.1/interactive/multibyte.html 에서 다음을 발견했습니다.

Name Bytes/Char
UTF8 1-4

유니 코드 문자가 PostgreSQL에서는 최대 4 바이트이지만 MySQL에서는 3 바이트로 위의 오류가 발생 했습니까?

---

None of these answers solved the problem for me. The root cause being:

You cannot store 4-byte characters in MySQL with the utf-8 character set.

MySQL has a 3 byte limit on utf-8 characters (yes, it's wack, nicely summed up by a Django developer here)

To solve this you need to:

1. Change your MySQL database, table and columns to use the utf8mb4 character set (only available from MySQL 5.5 onwards)
2. Specify the charset in your Django settings file as below:

settings.py

DATABASES = {
    'default': {
        'ENGINE':'django.db.backends.mysql',
        ...
        'OPTIONS': {'charset': 'utf8mb4'},
    }
}

Note: When recreating your database you may run into the 'Specified key was too long' issue.

The most likely cause is a CharField which has a max_length of 255 and some kind of index on it (e.g. unique). Because utf8mb4 uses 33% more space than utf-8 you'll need to make these fields 33% smaller.

In this case, change the max_length from 255 to 191.

Alternatively you can edit your MySQL configuration to remove this restriction but not without some django hackery

UPDATE: I just ran into this issue again and ended up switching to PostgreSQL because I was unable to reduce my VARCHAR to 191 characters.

---

I had the same problem and resolved it by changing the character set of the column. Even though your database has a default character set of utf-8 I think it's possible for database columns to have a different character set in MySQL. Here's the SQL QUERY I used:

    ALTER TABLE database.table MODIFY COLUMN col VARCHAR(255)
    CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL;

---

If you have this problem here's a python script to change all the columns of your mysql database automatically.

#! /usr/bin/env python
import MySQLdb

host = "localhost"
passwd = "passwd"
user = "youruser"
dbname = "yourdbname"

db = MySQLdb.connect(host=host, user=user, passwd=passwd, db=dbname)
cursor = db.cursor()

cursor.execute("ALTER DATABASE `%s` CHARACTER SET 'utf8' COLLATE 'utf8_unicode_ci'" % dbname)

sql = "SELECT DISTINCT(table_name) FROM information_schema.columns WHERE table_schema = '%s'" % dbname
cursor.execute(sql)

results = cursor.fetchall()
for row in results:
  sql = "ALTER TABLE `%s` convert to character set DEFAULT COLLATE DEFAULT" % (row[0])
  cursor.execute(sql)
db.close()

---

If it's a new project, I'd just drop the database, and create a new one with a proper charset:

CREATE DATABASE <dbname> CHARACTER SET utf8;

---

I just figured out one method to avoid above errors.

Save to database

user.first_name = u'Rytis'.encode('unicode_escape')
user.last_name = u'Slatkevičius'.encode('unicode_escape')
user.save()
>>> SUCCEED

print user.last_name
>>> Slatkevi\u010dius
print user.last_name.decode('unicode_escape')
>>> Slatkevičius

Is this the only method to save strings like that into a MySQL table and decode it before rendering to templates for display?

---

You can change the collation of your text field to UTF8_general_ci and the problem will be solved.

Notice, this cannot be done in Django.

---

You aren't trying to save unicode strings, you're trying to save bytestrings in the UTF-8 encoding. Make them actual unicode string literals:

user.last_name = u'Slatkevičius'

or (when you don't have string literals) decode them using the utf-8 encoding:

user.last_name = lastname.decode('utf-8')

---

Simply alter your table, no need to any thing. just run this query on database. ALTER TABLE table_nameCONVERT TO CHARACTER SET utf8

it will definately work.

참고URL : https://stackoverflow.com/questions/2108824/mysql-incorrect-string-value-error-when-save-unicode-string-in-django