django 項目中mysql 的編碼，數據庫遷移問題

以管理員的身份進入cmd 

net start mysql

mysql -u root -p

沒有密碼直接回車，進入mysql可以創建數據庫，

如退出mysql  執行 \q：命令

創建數據庫  記得指定編碼    create database orm_1128 character set utf8;  orm_1128是數據庫名字

 

修改數據庫的字符集mysql>use mydb

 

mysql>alter database mydb character set utf8;

 

 

如果報錯，

ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES)

是因為在mysql5.6版本以后，就需要輸入密碼了，

設置新密碼，123，下次再登錄的時候就要輸入密碼123，

mysql> set password for root@localhost = password('123'); Query OK, 0 rows affected, 1 warning (0.29 sec)

 

=====

查看數據庫  ，可以看到已經創建的表

mysql> show databases; +--------------------+ | Database | +--------------------+ | information_schema | | bookmanage1 | | bookmanage2 | | db1 | | db2 | | gu_orm | | myorm | | mysql | | performance_schema | | s5orm | | school | | sys | +--------------------+ 12 rows in set (0.06 sec)

選擇自己要修改的編碼的  數據庫，然后可以執行 \s; 命令 看到表的數據庫的編碼等信息，進行修改

mysql> use gu_orm; Database changed mysql> \s -------------- mysql Ver 14.14 Distrib 5.7.18, for Win64 (x86_64) Connection id: 70 Current database: gu_orm Current user: root@localhost SSL: Not in use Using delimiter: ; Server version: 5.7.18 MySQL Community Server (GPL) Protocol version: 10 Connection: localhost via TCP/IP Server characterset: latin1 Db characterset: latin1 Client characterset: gbk-------------------------------------------------------------- Conn. characterset: gbk----------------------------------------------------------------------- TCP port: 3306 Uptime: 14 hours 39 min 56 sec Threads: 4 Questions: 860 Slow queries: 0 Opens: 365 Flush tables: 1 Open tables: 256 Queries per second avg: 0.016 --------------  mysql> set character_set_client=utf8;------修改編碼 Query OK, 0 rows affected (0.05 sec)

 

 

創建表后如果出錯---

  File "C:\Python36\lib\site-packages\django\db\backends\mysql\base.py", line 30, in <module>
    'Did you install mysqlclient or MySQL-python?' % e
django.core.exceptions.ImproperlyConfigured: Error loading MySQLdb module: No module named 'MyS
QLdb'.
Did you install mysqlclient or MySQL-python?

C:\Users\lenovo\PycharmProjects\gu_ORM_11month>

沒有mysqldb（驅動）？？？

 

在python2之前的版本中是MySQLdb支持，到python3以后都用pymsql,

只需要調一下，在項目的下的__init__.py文件中 導入 import pymsql

寫上 pymysql.install_as-MySQLdb() ,就行，

 

在創建一對多的表的時候，記得把主表，一 的表放在 多 的表前面，要不生成數據庫時會報錯

執行python manage.py makemigrations 

python manage.py migrate

 

創建好數據庫以后，可以在cmd里看下數據庫，

use 數據庫名字  ，進入數據庫， \s 命令查看數據庫信息

show tables；  查看表

mysql> use gu_ORM
Database changed
mysql> show table
    -> ;
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '' at line 1
mysql> show tables;
+----------------------------+
| Tables_in_gu_orm           |
+----------------------------+
| auth_group                 |
| auth_group_permissions     |
| auth_permission            |
| auth_user                  |
| auth_user_groups           |
| auth_user_user_permissions |
| django_admin_log           |
| django_content_type        |
| django_migrations          |
| django_session             |
| gu_orm_book                |
| gu_orm_publish             |
+----------------------------+
12 rows in set (0.00 sec)

 

看到這里，就說明已經與數據庫連接上了，與pycharm里的表一樣

但每次都在cmd查數據不方便，就可以在pycharm里設置，

表就會出現，apply ，OK ，可以使用了

 

 一對多的表，先對一 的表插入數據，然后在多的表才能插入數據，因為先對多的表插入數據時，有一個外鍵，需要數據，所以先對一 的表插入數據，

關於數據庫的編碼問題

 show create table 數據庫的表名；  查看 表的編碼

alter table 數據庫的表名 charset utf8；  修改表的編碼

 

-------

 

重新遷移數據庫時會發生的錯誤，

C:\Users\lenovo\PycharmProjects\gu_ORM_11month>python manage.py makemigrations
No changes detected

記得在后面加上app名字

C:\Users\lenovo\PycharmProjects\gu_ORM_11month>python manage.py makemigrations gu_orm
Migrations for 'gu_orm':
  gu_orm\migrations\0001_initial.py
    - Create model Book
    - Create model Publish
    - Add field pu

blish to book

在執行python manage.py migrate

C:\Users\lenovo\PycharmProjects\gu_ORM_11month>python manage.py migrate
Operations to perform:
  Apply all migrations: admin, auth, contenttypes, gu_orm, sessions
Running migrations:
  Applying contenttypes.0001_initial... OK
  Applying auth.0001_initial... OK
  Applying admin.0001_initial... OK
  Applying admin.0002_logentry_remove_auto_add... OK
  Applying contenttypes.0002_remove_content_type_name... OK
  Applying auth.0002_alter_permission_name_max_length... OK
  Applying auth.0003_alter_user_email_max_length... OK
  Applying auth.0004_alter_user_username_opts... OK
  Applying auth.0005_alter_user_last_login_null... OK
  Applying auth.0006_require_contenttypes_0002... OK
  Applying auth.0007_alter_validators_add_error_messages... OK
  Applying auth.0008_alter_user_username_max_length... OK
  Applying gu_orm.0001_initial... OK
  Applying sessions.0001_initial... OK